National Research Council Canada

Additively manufactured transpiration cooling based on triply periodic minimal surface (TPMS) lattices has emerged as a promising thermal management strategy for next-generation gas turbines. However, the relative contributions of external film cooling and conjugate heat transfer (CHT), comprising internal convection and solid conduction, remain unclear. This study experimentally quantifies these contributions by independently measuring adiabatic film effectiveness (AFE) and overall film effectiveness (OFE) using pressure-sensitive paint (PSP) and temperature-sensitive paint (TSP), respectively. Three configurations were investigated: baseline effusion cooling with zero compound angle, effusion cooling with a 45° compound angle, and Koch-type TPMS-based transpiration cooling. The 45° compound-angle configuration enhanced both AFE and OFE relative to the baseline by improving lateral coolant spreading and suppressing jet lift-off, with the improvement primarily attributed to enhanced film cooling. TPMS-based transpiration cooling achieved substantially higher AFE and OFE over the investigated injection ratios through more effective coolant-film formation and enhanced internal heat transfer. CHT remained the primary contributor to the overall cooling performance of both effusion configurations, whereas film cooling became dominant for the TPMS configuration. The temperature-based comparison of AFE and OFE suggests a greater relative role of external film cooling in the investigated Koch-type TPMS configuration than in the effusion configurations under the tested conditions.

Abstract Urban flooding is becoming more frequent and damaging due to the combined effects of climate change and rapid urbanization, exposing the limitations of conventional risk-based flood-management approaches. Consequently, resilience-based strategies have gained attention for managing uncertainty, system complexity, and recovery capacity in urban flood contexts. Flood-resilience index (FRI) frameworks are widely used to operationalize resilience by integrating social, economic, infrastructural, institutional, and environmental dimensions into composite indicators. However, many existing FRI frameworks rely on static or snapshot-based assessments that inadequately represent feedback mechanisms, temporal evolution, and nonstationary flood regimes. This study presents a systematic literature review examining how geographic information systems (GIS), multicriteria decision-making (MCDM), and system dynamics modeling (SDM) have been applied individually and in combination to support urban flood-resilience assessment. Seventy-six peer-reviewed studies published between 2010 and 2024 were analyzed using qualitative content analysis and frequency-based quantitative synthesis. The review synthesizes dominant methodological practices and identifies recurring limitations related to indicator aggregation, weighting, spatial representation, uncertainty treatment, and temporal dynamics. The findings show that GIS–MCDM approaches enable spatially explicit and structured resilience assessment but are commonly constrained by static assumptions and criterion independence. SDM applications offer strong potential for capturing feedback-driven system behavior and for the long-term evolution of resilience, yet are rarely integrated with GIS-based MCDM FRIs. The paper proposes a formalized synthesis-based framework that integrates GIS, MCDM, and SDM to support spatially explicit and dynamically informed urban flood-resilience assessment. It highlights key research gaps for future development.

A mixed anaerobic microbial consortium producing short- and medium-chain fatty acids from CO2 and H2 was developed through mixed culture cultivation under a CO2/H2 atmosphere combined with the serial transfer technique to promote the growth of acetogenic and chain-elongating bacteria. Consequently, this enrichment was used to inoculate laboratory-scale microbial electrosynthesis (MES) cells that were continuously fed with CO2. To improve MES performance, a novel three-dimensional conductive polylactate cathode coated with a NiFeSn alloy was employed in one MES cell, while another MES cell was equipped with a carbon felt (CF) cathode. CO2 conversion and chain elongation were substantially increased in the NiFeSn cell. In this cell, a steady-state volumetric CO2 conversion rate of 2.4 L (Lc d)- 1 was achieved, with corresponding butyrate and caproate production rates of 1 g (Lc d)- 1 and 0.07 g (Lc d)- 1, respectively, at a current density of up to 4 mA cm- 2. The formation of C16-C18 fatty acids was also observed. 16S rRNA amplicon sequencing of the catholytes and cathodic biofilms revealed a significant shift in microbial populations from Clostridium-driven acetogenesis and chain elongation in the enrichment to one most likely driven by the genera Eubacterium, Megasphaera and Caproiciproducens in MES cells.

Global efforts toward carbon neutrality have intensified the demand for efficient and sustainable Li+ extraction from salt-lake brines. In this study, nanofiltration (NF) membranes with ultra-high Li+/Mg2+ selectivity were fabricated via interfacial polymerization using aminated lignin (AL) as an additive in the piperazine (PIP) aqueous phase and trimesoyl chloride (TMC) in the organic phase. Conductor-like screening model for real solvents (COSMO-RS) calculations and molecular dynamics (MD) simulations indicated that AL modifies the thermodynamic state of PIP in the aqueous phase and reduces its interfacial mobility, suggesting coupled thermodynamic and kinetic regulation of monomer transport. This regulation is consistent with the formation of a thinner and more structurally tailored polyamide (PA) selective layer. Zeta potential measurements revealed a reduction in membrane negativity after AL incorporation, supporting the enhanced Li+/Mg2+ selectivity. In a 2000 ppm salt solution with a Li+/Mg2+ ratio of 1:20, the optimized membrane (M-0.25 containing 0.25 wt% AL) achieved a Li+/Mg2+ selectivity of 51.2, representing a 7.4-fold improvement over the unmodified membrane without compromising water flux. These findings demonstrate the potential of AL as a bio-based reactive additive for enhancing Li+/Mg2+ selectivity in NF membranes, offering a promising strategy for lithium extraction from salt-lake brines.

This paper presents the first consolidated hydraulic design recommendations for the CoastalockTM armour unit, an eco-engineered single-layer armour system. Based on 306 individual sea-state test runs from four independent physical modelling campaigns conducted at the National Research Council Canada (NRC) and at Delft University of Technology (TU Delft), this study establishes a consolidated empirical basis for design. Hydraulic performance was expressed in terms of the stability number (Ns) and the Hudson coefficient (KD) for both permeable and impermeable cores with 2V:3H and 1V:2H slopes. The best-performing configuration (for a 2V:3H slope) consisted of protruded Coastalock units at 22.5% spacing on a permeable core; the resulting preliminary design values were Ns approximate to 2.8 and KD approximate to 15, which fall within the range reported for established single-layer systems such as Core-LocTM, XblocTM, Accropode IITM, and Cubipod (R). Armour unit spacing (defined as the intentional lateral gap between adjacent units expressed relative to the nominal armour diameter) and underlayer sizing were identified as the main effective parameters for hydraulic stability. The best performance for the tested configurations was observed for underlayer-to-armour layer nominal diameter ratios between 0.25 and 0.34, interpreted within the tested spacing, core permeability, and placement conditions. Overtopping analysis, calibrated against EurOtop formulas, produced gamma f values primarily between 0.65 and 0.70, reflecting the overtopping characteristics of Coastalock. Ecological monitoring is acknowledged as design context, as the unit cavities can function as water-retaining tidal pools and shaded refuges; however, the recommendations presented here are focused on hydraulic stability, overtopping, underlayer response, and toe/rear side response observations. These findings indicate that Coastalock has potential as a dual-purpose single-layer armour unit. The recommendations based on the tested structural configurations and hydraulic conditions provide a research-based framework for preliminary hydraulic design of single-layer eco-engineered Coastalock armour units.