National Research Council Canada Research Articles

LOW-CRESTED AND EMERGENT BREAKWATERS WITH ECO-FRIENDLY ARMOUR UNITS

Artificial coastal defense systems (such as concrete armour units) frequently host less diverse aquatic populations than natural environments and feature higher concentrations of invasive species (Dafforn et al., 2009). Therefore, coastal structures need to be designed or refitted to achieve sustainable goals through the application of ecological engineering solutions applied to coastal defence structures and for the ecosystem, marine habitat, and biodiversity improvement. Ecological engineering, which integrates ecosystems with engineering principles to construct coastal structures that benefit both humans and the ecosystem, is growing as a means of reducing the adverse ecological impacts of coastal infrastructure (Mitsch & Jorgensen, 2003). Thus, creating new eco-friendly breakwater design guidelines is critical and will benefit from the multidisciplinary involvement of marine biologists and ecologists. The purpose of this experimental modelling study was to provide data on the hydraulic performance and stability of low-crested and emergent rubble mound breakwaters (RMBW) constructed using ecologically friendly armour units under various wave conditions. The University of Ottawa, the National Research Council of Canada (NRC), and ECOncrete collaborated to develop and conduct the physical testing program. Several breakwater models were tested to evaluate their performance, as the idea of an eco-friendly breakwater is still a new area of research. Thus, this experimental program is essential to promote environmentally-friendly armour units in the design of new coastal structures (such as Baker et al., 2018), as well as ecological retrofitting of existing coastal structures. The physical tests were conducted between June 2023 and August 2023 in the Large Wave Flume of NRC’s Ocean, Coastal, and River Engineering Research Center in Ottawa, Canada. ECOncrete's Coastalock armour units were tested in various configurations at a 1/15 scale using two-dimensional low-crested and emergent RMBW models. The hydraulic performance and failure mechanisms of these environmentally-friendly breakwater models were tested under severe wave conditions.

Large-Scale Experimental Model Of Edge Treatments For Constructed Salt Marshes

Large stretches of Canada’s coastlines are lined with legacy dykes (or levees) to provide protection against coastal flooding and erosion. However, future sea-level rise presents a risk to these structures, which may result in the dykes being under designed when exposed to future water levels and wave conditions. Under certain conditions, these dykes can be augmented with a coastal saltmarsh to create a living dyke, which allows for the existing dyke to be more resilient against sea level rise without the need to retrofit the dyke with a higher crest elevation or larger armour stone. The coastal saltmarsh is able to attenuate storm waves, resulting in lower wave energy at the dyke, while also attracting and retaining sediment to combat coastal erosion. The Living Dyke project in Boundary Bay, Canada is a pilot project being used to test the living dyke concept by placing sediment and planting salt marsh vegetation in the foreshore combined with upgrades to the existing dyke. Kerr Wood Leidal Associates Ltd. prepared a preliminary design which incorporated four different edge treatment features that are to be installed at the offshore edge of a newly constructed salt marsh platform in order to attenuate wave energy and retain the placed sediment before the planted vegetation can be established. The proposed edge treatment features included a natural sand edge, a rounded gravel berm, an oyster-shell filled bag berm, and a brushwood dam. Large scale (full scale for all edge treatment feature tests except for the brushwood dam which was conducted at half-scale) physical model experiments were carried out by the National Research Council of Canada’s Ocean, Coastal and River Engineering Research Centre in their Large Wave-Current Flume to investigate the performance, including stability of the edge treatment features, wave attenuation ability, and stability of the salt marsh platform, of these edge treatment features under varying water level and wave conditions that are present at Boundary Bay.

Investigation of differential diffusion in lean, premixed, hydrogen-enriched swirl flames

Hydrogen combustion is a promising alternative to fossil fuel combustion in an effort to reduce our carbon footprint. However, hydrogen combustion is prone to thermodiffusive instabilities largely dependent on differential diffusion, a phenomenon that can lead to higher probabilities of flashback in industrial burners, given hydrogen’s high reactivity and diffusivity. This paper evaluates low-swirl flames of methane and air enriched with hydrogen to highlight the onset of differential diffusion. Testing was conducted in a fully controllable swirl burner, where bulk velocity Uav = 13 m/s and swirl number S = 0.6 were kept constant for each hydrogen-methane blend to isolate increases in flame surface area from increases in turbulence intensity. Furthermore, each fuel blend of hydrogen and methane is evaluated at the same laminar flame speed of SLo = 0.267 m/s to isolate flame stretch effects on the turbulent burning rate. Combined hydroxyl (OH) PLIF and stereoscopic PIV at the National Research Council of Canada were used to analyze the OH fluorescence in a 2D-3C velocity field for each flame condition. High-speed PIV at McGill University was used to resolve local flame phenomena, such as local flame displacement velocity and flame stretch rate. Using these techniques, it can be observed that the flame displaces axially in response to turbulent flame speed while exhibiting increases in flamefront wrinkling. This increased corrugation due to flame stretch is highlighted in the PDFs of local curvature and κSf and is further evidenced by a shift towards positive curvatures (κ> 0) for increasing H2 volume fraction. This trend suggests that there is a strong correlation with increases in turbulent burning rate and positive curvature as a result of differential diffusion, but it is not necessarily a control mechanism of the most forward propagating points proposed by the theory of leading points.

Numerical Icing Simulations of Cylindrical Geometry and Comparisons to Flight Test Results

There is growing interest in government and industry to use numerical simulations for the Certification by Analysis of aircraft ice protection systems as a cheaper and more sustainable alternative to wind-tunnel and flight testing. The ice accretion on a cylindrical test article mounted under the wing of the National Research Council of Canada’s Convair-580 research aircraft during a flight test in Appendix O icing conditions was simulated using Ansys FENSAP-ICE™. A multishot simulation with input parameters averaged over the full icing period led to an increased level of liquid catch and ice accretion (by mass), and a broader ice profile when compared to a simulation with shot-averaged input parameters. An additional simulation using Ansys’ proprietary “extended icing data with vapor solution” method for calculating heat fluxes at the icing surface resulted in a broader ice profile in comparison to the classical technique, which produced a similar amount of accretion by mass. No combination of simulation settings, input parameters, and multishot methods tested in this study generated the same level of surface detail observed during flight testing, however, the amount of ice accretion, general location of ice features, and formation processes were in good agreement with the experimental results.

Wind Effect on External Fire Spread through Openings under the Protection of Horizontal Projections or Vertical Spandrels—A Numerical Study

A numerical investigation has been conducted to analyse the effect of wind on the vertical spread of fire through a front opening in a building’s external walls. The study utilises a building geometry established from previous experimental work conducted by the National Research Council of Canada (NRCC). A horizontal projection or a vertical spandrel is introduced above the opening of the compartment of fire origin. The purpose of the projection or spandrel is to inhibit the vertical spread of the fire, following the relevant requirements in the Australian National Construction Code (NCC). A computational fluid dynamics (CFD) package for fire-driven fluid flow, namely the Fire Dynamics Simulator (FDS), is employed to simulate the fire behaviour. The FDS model is validated against the NRCC’s experimental results, and a good agreement is achieved. Winds from three horizontal directions (front wind is normal to the opening, side wind is parallel to the opening, and back wind is from behind the building) have been investigated, with speeds ranging up to 10 m/s for each wind direction. Front wind speeds below 1 m/s are found to slightly enhance the vertical spread of the fire, while speeds exceeding 1 m/s are inclined to promote horizontal spread. The impact of side wind on the vertical fire spread was also found to vary with wind speed. The increase in the speed of back wind influences flame buoyancy, resulting in an augmented vertical fire spread. Furthermore, the numerical results reveal that a vertical spandrel of 1100 mm height is less effective in preventing vertical fire spread through openings, compared to a 1100 mm deep horizontal projection. The study suggests that the fire safety design in reducing the hazard of vertical fire spread through openings in buildings’ external walls could be further improved if the effect of wind is considered.

Systematic Assessment of Electrode Wettability for Vanadium Redox Flow Batteries

Vanadium redox flow batteries (VRFBs) are a promising energy storage technology due to their advantages such as long-life cycle and scalability. In these systems, porous electrodes such as carbon paper and carbon felts have been used because of their desirable properties such as good acid resistance and low cost. However, these materials may have poor reversibility and wettability, which can negatively affect the system performance. Recently, different activation methods have been proposed to enhance physico-chemical properties and overcome these limitations. Among different methods, surface treatments have been commonly used in the literature [1-5] since they can introduce desirable functional groups (e.g., oxygen, nitrogen) and enhance electrochemically active surface area (ECSA), which is believed to be the main mechanisms for electrode performance improvement. Although it is suggested that higher electrode performance can be achieved by enhancing wetted or active surface area [6], there is still a disparity in how to assess relevant wetting properties, since wettability assessment is often neglected and performance assessment is usually done based on VRFB cycling test results, which is costly and time consuming.Static contact angle (CA) is commonly used to characterize electrode wettability and evaluate the effect of different treatments on the electrode surface. However, this technique offers a limited understanding and superficial analysis, since samples are either classified as hydrophobic or hydrophilic, showing no correlation to electrochemical performance. Moreover, CA measurements are not adequate for porous electrodes, since porosity and surface roughness can impact on contact angle results. In the present work, we propose to use the method of standard porosimetry (MSP) and cyclic voltammetry (CV) to evaluate the impact of surface treatments on electrode wettability from a complete physical (pore size distribution), chemical (functional group density), and electrochemical (electrochemically active surface area) perspective. These tools offer richer information than basic CA measurements and only take a few hours to be performed, thus reducing the assessment time and cost compared to VRFB assembly and cycling tests.Preliminary results show that both MSP and CV techniques can provide useful information regarding physical and chemical properties that can correlate electrode wettability to electrochemical performance. While MSP results can provide electrode morphology (pore size distribution, porosity, specific and wetted surface area), CV measurements can provide surface chemistry information (functional groups density) and electrochemically active surface area (capacitance). Thus, both tools can be used synergistically to investigate how different treatments impact both physical and chemical properties and how wetting properties impact electrode performance. Achieving high performance is essential to increase system energy density and decrease both capital and operational cost, making VRFBs more competitive and suitable for grid-scale storage of renewable energy, having positive environmental impacts and facilitating sustainable transition. Acknowledgements This research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Foundation for Innovation (CFI), British Columbia Knowledge Development Fund (BCKDF), Western Economic Diversification Canada (WD), Canada Research Chairs (CRC), and the National Research Council of Canada (NRC). Technical support from Elizabeth Fisher and Jonas Stoll is also acknowledged.

Impact of Missing Cathode Catalyst Layer Areas on Performance and Durability in PEM Fuel Cells

High throughput and product quality are essential for the scalable production of cost-effective polymer electrolyte membrane fuel cells (PEMFCs). Therefore, it is important to understand the possible implications of various material defects that could appear in the manufacturing process. During the fabrication and assembly of catalyst-coated membranes (CCM)s, the catalyst layers (CL)s may contain void regions of partially missing material due to deficient deposition or unintentional removal, which could affect fuel cell performance and durability [1], [2]. For instance, CL cracks have been shown to expand and propagate into more harmful membrane cracks [3]–[5]. In addition, local thickness differences in CCMs arising from missing CL sections or deficiencies in other components could result in local stress concentration and susceptibility of membrane pinhole formation [6], [7]. Therefore, in general, a missing section of the CL area or other similar irregular features in the CL of a CCM may imply categorizing these CCMs as defective (i.e., scrap) and excluding them for fuel cell assembly. However, on the contrary, M. Kim et al. found increased cell performance for cracked CCM via tensile forces (within the elastic strain region) due to improved mass transport and decreased membrane resistance [8].Consequently, to improve the understanding of CCM defects, the present work investigates how different missing cathode catalyst layer (CCL) areas affect the PEMFC performance and durability. In more detail, we prepared via ultrasonic spray coating 25 cm2 active area MEAs with 4.0, 5.9, and 8.5% missing CCL areas obtained by masking (as shown in the Figure), and compared these to defect-free CCL baselines.The results of this study feature a comprehensive assessment of the fuel cell performance of the defective MEAs compared to the baseline MEAs. This includes extraction of the membrane and charge transfer resistances from the missing CCL areas via medium- and high-frequency equivalent circuit modeling of in-situ electrochemical impedance spectroscopy (EIS) data at a current density of 0.1 A/cm2 and contact, membrane, charge transfer, and mass transfer resistances at a current density of 1 A/cm2. Findings on the influences on the electrochemical surface area, hydrogen cross-over current density, and double-layer capacitance from such missing CCL area will also be presented. Results from chemical/mechanical and electrochemical cycling tests will also be shown regarding the effect on durability from the missing CCL area.The results from this work may benefit the economy of scale for high-volume fuel cell manufacturing by reducing unnecessary CCM replacements and materials waste by providing a threshold for an acceptable missing CCL area.AcknowledgementsFunding for this research was provided by National Research Council Canada’s Clean and Energy-efficient Transportation (CEET) program and Canada Research Chairs.

Characterization of a Novel Additive Manufacturing Micromix Nozzle Burning Methane to Hydrogen

Abstract As the energy landscape transitions to low/zero-carbon fuels, gas turbine manufacturers are targeting fuel flexible operation with natural gas, syngas, and hydrogen-enriched mixtures. Having a single geometry that can support the different fuel blends requested by clients can accelerate the transition to cleaner energy generation and mitigate the environmental impact of gas turbines. Toward this goal, micromix combustion technology has received significant interest, and when coupled with additive manufacturing, novel injector geometries with unique configurations may be capable of stabilizing premixed, partially-premixed, and diffusion flames using fuel mixtures ranging from pure methane to pure hydrogen. In this work, a preliminary investigation of this micromix concept is performed in the Atmospheric Combustion Rig at the National Research Council (NRC) Canada. Flame stability maps are obtained for fuel lean mixtures of H2/CH4 ranging from 0/100, 70/30, 90/10, to 100/0%, by volume. Multiple flame shapes are observed depending on the fuel mixture and combustion mode selected. Particle image velocimetry (PIV), OH, and acetone planar laser-induced fluorescence (PLIF), and acoustic measurements provide additional insights into the combustion process of these novel burners to better understand the stability mechanisms. The quality of the fuel–air mixing from the premixed and micromix injectors is assessed using acetone as a tracer for the fuel, while simultaneous OH-PLIF measurements provide an indication of the postflame regions in the flow. Acoustic measurements complete the current dataset and provide combustion dynamics maps measuring the normalized pressure amplitudes and identifying the dominant frequencies. The preliminary characterization of this additive manufacturing (AM) micromix nozzle shows promising fuel flexibility with wide stability margins and low combustion dynamics for this single nozzle burner.

A precision sound pressure level measurement system

Noise pollution affects human and wildlife. It is in the public interest to reduce noise levels. Measures to be taken to reduce the noise are normally expensive and must be based on facts and reliable measurements of noise. Therefore, sound pressure level measurements are key evidence to determine whether there is a breach of noise limits. The sound pressure measurement method should comply with the metrological principles concerning validation, measurement traceability and estimation of measurement uncertainty as stated in ISO/IEC Directives, Part 2, Principles and rules for the structure and drafting of ISO and IEC document. For this reason, a precision sound pressure measurement system has been developed at the National Research Council Canada. The system utilizes the latest advances in digitization and is metrologically transparent, facilitating the evaluation of measurement uncertainties. In this paper, the design and implementation of the system based on IEC 61672-1, Electroacoustics - Sound level meters - Part 1: Specifications is described. The technical challenges, such as truncation, are discussed. Closed-form solutions are obtained for typical sinusoidal sound signals. Experiments were conducted for the validation of the system. The measurement results are presented showing that the discrepancy between theoretical calculations and measurements is only 1.6 ppm.

On the test method for short-term level fluctuation of sound calibrators

Most noise bylaws state that a precision sound level meter which meets the International Electrotechnical Commission Publication 651 or the American National Standards Institute S1.4-1983 needs to be used for noise measurements. To ensure measurement accuracy, sound calibrators are used to check the sound level meter accuracy before and after any such measurements, as required by most noise regulations. The sound calibrator itself needs to be calibrated routinely and traceable to national standards. The International Standard IEC 60942, Electroacoustics - Sound calibrators, specifies performance requirements for the sound pressure level, short-term level fluctuation, frequency, and distortion and associated test methods. However, the test method for short-term level fluctuation specified in IEC 60942 is problematic. The short-term level fluctuation cannot be measured in some cases using the method specified in IEC 60942. In this paper, a detailed theoretical analysis is presented addressing this particular issue. Closed-form solutions are obtained for typical sinusoidal sound signals. Two experimental setups and measurement results for the validation of the theoretical analysis are also presented. One uses a commercial sound level meter and the other uses a precision sound pressure measurement system developed recently at the National Research Council Canada.

Vibration reduction indices for junctions between cross-laminated timber floors and lightweight timber framed walls

Cross laminated timber elements are often used as the floors and the external walls in mass timber buildings in Canada, but the internal walls of these buildings are typically lightweight timber framed walls. The calculation of the flanking transmission loss and the apparent sound transmission class for the mix of lightweight and mass timber constructions requires the laboratory measured vibration reduction indices or flanking level differences of the different flanking paths. Junctions constructed in the new four room flanking facility at the National Research Council Canada have been used to evaluate both the vibration reduction indices and the flanking level differences of a cross laminated timber floor connected to lightweight timber walls.

Comparison between noise annoyance and noise sensitivity

This study examined the relationship between noise sensitivity and noise annoyance. As part of a collaboration between the National Institute of Advanced Industrial Science and Technology in Japan and the National Research Council Canada related to the acoustic requirements for dwellings intended for aging in place, a pilot subjective study of noise annoyance was conducted. Sixty participants in the subjective study were asked to also complete a shortened Weinstein Noise Sensitivity Scale. The results were divided into two groups based on their hyper- or hypo-sensitivity to noise. The results showed that the noise annoyance of impact sound was perceived differently by the hyper-sensitivity group and the hypo-sensitivity group.

The role of standards laboratories in reducing uncertainty in clinical dosimetry: A Canadian perspective

As a National Metrology Institute, the National Research Council Canada (NRC) provides confidence in measurement results, and data traceable to SI units. This paper outlines some of the ways that the NRC contributes to reducing measurement uncertainty in clinical medical physics dosimetry. These activities include, (i) the improvement of existing primary standards and traceability for established beam modalities, such as MV photon and electron beams; (ii) improving measurement accuracy for new beam modalities through the development of transportable systems which permit operation at the user’s facility; (iii) contributing to new dosimetry protocols, best practice reports and educational outreach; and (iv) supporting the verification of clinical implementation by offering dosimetry auditing capabilities through coordination with the clinical medical physics community.

An investigation of rain-wind induced vibrations on stay cables in a novel range of operating conditions

The large-scale rain-wind induced vibration (RWIV) dynamic test rig at the National Research Council Canada (NRC) was used in the current work to evaluate the vibration characteristics of a 0.218 m diameter smooth stay cable, for two cable inclinations and a wide range of yaw-angle conditions. The structural damping ratio was in the range of 0.05% to 0.11% and the heave frequency was approximately 1.23 Hz for a cable with a moving mass of 217 kg. The presence of RWIV was investigated at an inclination angle of 30° from the horizontal over a yaw-angle range of 25° to 45°and for an inclination angle of 55° over a yaw-angle range of −40° to ＋45°. An upper rivulet was present when vibrations were observed. For positive yaw angles, the upper rivulet was characterized by a thin line of water, approximately 5 to 10 mm wide, running along the entire length of the inclined cable on the windward side and moving along the cable span with a serpentine motion. For negative yaw angles, the upper rivulet was located near top of the cable or on the leeward sector of the cable, was wider than the rivulets observed for positive yaw angles, and was not observed to move in a serpentine motion. RWIVs were observed for each yaw angle that was investigated, including at negative yaw angles, with a maximum amplitude of motion of ±150 mm (∼0.7D). The direction of the rain impingement was an important factor affecting the formation and characteristics of the upper rivulet at the surface of the cable and, for the onset for vibrations. RWIVs were observed for wind speeds between 5 and 12 m/s. The Reynolds number corresponding to the onset of RWIV tended to increase with larger yaw angles in the positive yaw-angle range. At an inclination angle of 30°, the onset of RWIV ranged from 1.2×105 at a yaw of 25° to 1.4×105 at a yaw of 45° while at a cable inclination angle of 55°, the onset of RWIV ranged from 1.08×105 at a yaw of 25° to 1.25×105 at a yaw of 40°. The onset of vibrations for a yaw angle of 0° was at 0.77×105 for a cable inclination of 55°. RWIV was initiated at lower Reynolds numbers at an inclination angle of 55° for negative yaw angles, with vibrations observed at wind speeds as low as 5 m/s (Reynolds number of 0.7×105). The results confirmed the presence of RWIV in well-understood conditions and have effectively expanded the range of conditions over which RWIV has been observed in a wind tunnel. The expanded range over which RWIV was observed includes vibrations at an inclination angle of 55°, vibrations at a yaw angle of 0°, and vibrations at negative yaw angles from −10° to −40°.

Ethnic minorities' mentality and homosexuality psychology in literature: A text emotion analysis with NRC lexicon

As a significant subfield of natural language processing (NLP), text emotion analysis has been extensively researched and applied in various domains, such as media, education, and medicine. It has shown significant results in annotating blog posts that rely on an extensive corpus of short phrases. However, in interdisciplinary fields like literary pragmatics, character emotion analysis in literature becomes crucial. Despite the importance of this topic, there are fewer studies, especially for niche subjects such as ethnic minorities' mentality and homosexuality psychology. This paper examines the effectiveness of the widely used lexicon National Research Council of Canada (NRC) in detecting metaphorical words in the famous homosexual novel Maurice. To increase the accuracy of the test, we classified and cleaned the stop words using the Natural Language Toolkit (NLTK) before the analysis step. Our results indicate that the lexicon is able to demonstrate reasonable emotional changes in the story.

The booming party walls being constructed in the skyscrapers of Toronto

With eight new 300 m or higher buildings and another ninety shorter skyscrapers either under construction or proposed for the booming Toronto real estate market, there is no shortage of work for acoustic consultants in Toronto at the moment. Most of the high-rise buildings allocated for residential use include concrete floors and ceilings, glass curtain walls, and lightweight, steel stud gypsum board interior walls. A party wall design that has become popular among architects is a double steel stud wall with one or more layers of gypsum board attached to the studs in the gap between the rows of studs in addition to the gypsum board attached to the exterior of the studs. Typically, the transmission loss values for the wall designs used to demonstrate compliance with the building code are those for single stud walls with equivalent stud gauges and numbers of exterior layers of gypsum board. Due to the lack of available data, the National Research Council of Canada measured the transmission loss of many of these wall designs and found that adding the gypsum board in the cavity between the rows of studs has a significant effect on the transmission loss below 200 Hz.

NEW INSIGHTS ON USING SCALED MARSH PLANT SURROGATES FOR WAVE ATTENUATION

It has been widely demonstrated in literature that coastal marshes provide positive ecosystem services related to coastal protection, including wave attenuation, storm surge reduction, and erosion prevention (Moller et al., 2014; Wang et al., 2021; Paul and Kerpen, 2021). Physical modelling presents a useful tool for investigating the coastal protection function provided by marsh vegetation in a controlled, repeatable environment, to inform design of nature-based coastal protection strategies, or “nature-based solutions” (NBS). To date, physical modelling studies have been used to investigate the influence of plant biophysical parameters (stem width, stem height, stem flexibility) and hydrodynamic conditions on wave attenuation (e.g., Augustin et al., 2009; Anderson and Smith, 2014; Moller et al., 2014; Ozeren et al., 2014; van Veelen et al., 2020). Such studies have predominantly used surrogate vegetation due to the logistical challenges and facility requirements associated with live plant experiments. Furthermore, most studies have been performed at or near full-scale to reduce uncertainties and scale effects associated with downscaling vegetation, particularly where Reynolds number similarity cannot be preserved (Blackmar et al., 2014). To address existing knowledge gaps related to physical modelling of marsh vegetation at small-scale, experiments were conducted in a 63 m long by 1.22 m wide wave flume at the National Research Council of Canada’s Ocean, Coastal and River Engineering Research Centre, Ottawa, in collaboration with the University of Ottawa and the Institut National de la Recherche Scientifique, Quebec City.

82Se Metabolically-Labeled Yeast as a Matrix-Matched Isotope Dilution Standard for Quantification of Selenomethionine.

Selenized yeast is commonly used as a highly bioavailable source of selenium in dietary supplements and feed additives and is used in research settings in various disciplines due to the large number of selenium-containing metabolites formed during growth. With the selenomethionine being the major form of selenium present in selenized yeasts, its accurate quantitation is essential, however, values are frequently underestimated due to the costly and time-consuming hydrolysis-based sample preparation required to release the selenoamino acid from proteins for analysis. The National Research Council Canada has developed an 82-Se-enriched selenized yeast Certified Reference Material, SEEY-1 (DOI: 10.4224/crm.2023.seey-1) intended to be used as a matrix-matched spike material for isotope dilution analysis of selenized yeasts. The total selenium and selenomethionine contents of SEEY-1 were determined to be 322.1 ± 4.8 mg/kg (k = 2) and 635.6 ± 16.8 mg/kg (k = 2), respectively. Here we present results on the preparation of the 82-Se-enriched yeast, the certification process, and provide an example of the use of SEEY-1 as a matrix-matched spike for the analysis of selenomethionine in a sample of selenized yeast. We demonstrate here that SEEY-1 is able to compensate for the partial digestion of yeast proteins and provide reliable analytical data on Se amino acid content in under an hour instead of the 16 hours required for conventional complete acid hydrolysis.

Peer Review Statement

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single Anonymous• Conference submission management system: Morressier• Number of submissions received: 21• Number of submissions sent for review: 21• Number of submissions accepted: 8• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 38.1• Average number of reviews per paper: 2• Total number of reviewers involved: 30• Contact person for queries: Name: Andrew Todd Email: andrew.todd@nrc-cnrc.gc.ca Affiliation: National Research Council of Canada

Production and certification of BOTS-1: bovine muscle-certified reference material for incurred veterinary drug residues.

A freeze-dried bovine muscle-certified reference material (CRM), known as BOTS-1 (DOI: https://doi.org/10.4224/crm.2018.bots-1 ), containing incurred residues of commonly used veterinary drugs was produced and certified for the mass fraction of eight veterinary drug residues. Value assignment was carried out using liquid chromatography tandem mass spectrometry (LC-MS/MS) methods in conjunction with isotope dilution and standard addition approaches involving stable isotope internal standards. Data from the National Research Council of Canada (NRC), Canadian Food Inspection Agency (CFIA), United States Department of Agriculture (USDA), and the Federal Office of Consumer Protection and Food Safety in Germany (BVL) were used for value assignment. Results for two drug residues were also obtained through an international inter-laboratory comparison CCQM-K141/P178 organized under the auspices of the International Bureau of Weights and Measures (BIPM). Quantitative NMR (1H-qNMR) was used to characterize primary standards of all veterinary drugs certified. The certified mass fractions of the veterinary drug residues were 490 ± 100µg/kg for chlorpromazine, 44 ± 4.4µg/kg for ciprofloxacin, 3.3 ± 1.4µg/kg for clenbuterol, 9.5 ± 0.8µg/kg for dexamethasone, 57 ± 4.8µg/kg for enrofloxacin, 3.0 ± 0.4µg/kg for meloxicam, 12.4 ± 1.2µg/kg for ractopamine, and 2290 ± 120µg/kg for sulfadiazine with expanded uncertainties quoted (95% confidence) which include the effects due to between-bottle inhomogeneity, instability during long-term storage and transportation, and characterization.