Abstract Purpose Proficiency with consensus standards is essential for biomedical engineers to develop effective, safe, and compliant medical devices. Here, we describe a novel, standards-based module that enhances student ability to interpret, apply, and revise consensus standards through round-robin testing. Methods A hands-on learning module was designed and implemented in an upper-level biomedical engineering course. The curriculum incorporated the use of a custom-designed tensile testing device alongside a mock standard to introduce students to protocol development, standards revision, and real-world challenges in testing variability. Eight student teams conducted round-robin testing using devices configured with deliberate adulterations. Learning objectives (LO) include (1) defining round-robin testing, (2) interpreting a consensus standard, and (3) revising a consensus standard. Assessment included a Standard Revision Report and a post-module survey. Results From the post-module survey, students were only somewhat able to define round-robin testing (LO1; average score of 0.4/1). From the Standard Revision Report, teams reliably identified elements from the mock standard to apply for their own tensile testing (LO2; average score of 2.5/3). Also from the Report, teams reliably revised the mock standard to address the adulterations they found (LO3; average score 1.5/2). After the module, students reported confidence in extracting requirements from standards, applying them to verification testing, and identifying potential limitations in testing protocols. Moreover, students found the activity effective for increasing their confidence in preparing them for industry applications, though some suggested extending the module duration and improving instructional clarity for increased effectiveness. Conclusion This study describes the development and implementation of a standards-based module in biomedical engineering. Ultimately, students engaged in higher-order problem-solving and improved their understanding of standards implementation, testing variability, and collaborative verification processes. The findings suggest that this curriculum model could be expanded across engineering disciplines to enhance workforce preparedness in quality engineering and R&D roles.

Segmentation of phases in low carbon steels by weak-supervised deep learning: a round robin test on different microscopes and EBSD systems

ObjectiveThe consortium ALT‐SPF performed an international round robin test to characterize non‐invasive methods as alternatives to the erythema‐based testing of sun protection factor (SPF) according to ISO 24444:2019.MethodsHybrid diffuse reflectance spectroscopy (HDRS) based on a multi‐lambda LED light source uses in vivo reflectance spectra on skin to determine sunscreens in vivo absorbance spectra, which are fused with respective in vitro absorbance spectra measured as thin films transmission as described in ISO 24443:2019. As a part of the ALT‐SPF consortium initiative, a blinded study on 64 samples was performed in four European laboratories. After further improvements of the method, a blinded re‐evaluation based on 16 samples was performed. Five statistical acceptance criteria for new methods were assessed by an independent statistical institute to compare the obtained results to the reference methods for SPF and UVA‐PF.ResultsThe initial ALT‐SPF study 1 showed that the bias criterion was acceptable, while the reproducibility and interlaboratory variability needed further improvement. The re‐evaluation study 2 showed that the reproducibility and interlaboratory variability could be considerably improved. Using only n = 10 volunteers and a bias correction based on the initial ALT‐SPF study 1 data, the SPF results of the re‐evaluation study 2 were close to the acceptance criteria of the ALT‐SPF study with criterion 1 (reproducibility) and only 11% over the limit defined by the performance of the gold standard. The UVA‐PF results were within the acceptance limits for the acceptance criteria, except criterion 3 being in the ‘almost met’ range. The re‐evaluation study indicates that the method has a comparable precision to the gold standard methods ISO 24444 and ISO 24443.ConclusionThis study showed that the LED‐HDRS method is capable of providing reasonable non‐invasive SPF and UVA‐PF results and that the performance shows close alignment to the reference method. Thus, it can be proposed as an alternative method to the current standards ISO 24444 and ISO 24443.

From proof to practice - Sampling and analysis for simplified quantification of siloxanes in biogas.

Experimental validation of standardised procedures for added resistance and ship motion estimates in regular waves by round-robin tests

PEMWE has emerged as an energy storage and conversion solution for green H2 production. It has exceptional advantages such as cleanliness, compactness, short response time etc. Membrane electrode assembly (MEA) is the critical component for PEMWE. The sandwich-structured MEA typically consists of a membrane as well as a catalyst layer (CL) and a gas diffusion layer (GDL) on the cathodic and anodic sides. The catalyst coated membrane (CCM) is the key component of the MEA, consisting of a polymer electrolyte membrane coated with anode and cathode catalyst layer on each side. Currently IrO2 is still the state-of-the-art catalyst for OER and Pt for the hydrogen evolution reaction (HER), and IrO2 loading is still high (~ 2 mg cm-2), especially in industry.To achieve optimal performance, the CCM needs to be activated in the PEMWE cell, e.g. conditioning at different current densities for certain time. A variety of CCM activation procedures were reported in the literature. Babic et al conditioned the CCM for 12 hours by cycling the current density between 1 and 2 A cm−2 in 5 min intervals at 60°C [1]. Liu et al conditioned the CCM by ramping the current to 2 A cm−2 and holding it for 4 h at 80°C [2,3]. In a benchmarking and round robin testing, Bender et al developed a test protocol to activate the CCMs by operating the PEMWE at the testing temperature e.g., 60°C or 80°C at 0.2 A cm-2 for 30 minutes, then at 1 A cm-2 for 30 minutes, followed by controlling the cell at 1.7 V until variation was less than 1% per hour or for 15 hours [4,5]. Kwan et al activated the CCM by holding the PEMWE at 20, 40, and 60 mA cm-2 for 10 minutes each [6]. Although the PEMWE could reach optimal and stable performance after these activation procedures, the catalyst composition was not expected to change during the activation procedure. It was reported that Ir metal has higher catalytic activity toward OER than IrO2 [7], thus partly converting IrO2 to Ir metal might improve the PEMWE performance.In this work, CCMs were prepared using commercial IrO2. The CCMs were tested in PEMWE. Stable performance was obtained after conventional activation process. To further improve the performance, cyclic voltammetry in the potential range of -0.2 – 1.0 V were applied to the CCM in order to partially reduce the IrO2.Fig. 1 shows the polarization curves of the commercial CCM, 7%-Alfa CCM, and the 7%-Alfa CCM that had been scanned 33 cycles CV. It can be seen that the 7%-Alfa CCM showed higher cell voltage than the commercial CCM at all current densities, especially at low and medium current densities. The 7%-Alfa CCM showed cell voltage of ~ 20 mV higher than the commercial CCM. However, after 33 cycles CV, the performance of the 7% -Alfa CCM was significantly improved. The 7%-Alfa CCM after 33 cycles CV demonstrated cell voltage decreased by ~20 mV, comparable to that of the commercial CCM, indicating that CV scanning did improve the PEMWE performance.Fig 2 compares the cycle 2, and cycle 33 CV of the 7%-Alfa CCM. The cycle 2 CV represents the original state of the IrO2 in the catalyst layer, showing a normal IrO2 CV feature [8]. The wide oxidation peak at ~0.35 V is due to Ir0/3+, and the much wider redox peak at about 0.75 V is due to Ir3+/4+ [8-10]. The small reduction current between -0.15 – -0.2 V is due to H2 evolution. Ir metal is a hydrogen evolution reaction (HER) catalyst, and it promotes HER [7]. This indicates that there might be small amount of Ir metal present in the original IrO2 catalyst. At cycle 33, an oxidation peak appeared at ~0.05 V, which is attributed to hydrogen desorption on Ir metal. The Ir0/3+ peak shifted to more positive potential and the peak current increased significantly. Also the HER current below 0 V increased significantly, and the HER current is > 0.7 A at -0.2 V. All these features indicate that the Ir metal amount in the catalyst layer is increased, and that the PEMWE performance improvement might be due to the presence of Ir metal. Optimal CV cycling condition and the CCM performance will be presented. Figure 1

Abstract As superconducting wires have become more prevalent, it has become increasingly important to establish reliable and standardized methods for evaluating their electromechanical properties (EMPs) at cryogenic temperatures. An international round-robin test (RRT) was conducted to assess the EMPs of four commercially available high-temperature superconducting (HTS) tapes as an activity to establish a standard for the EMP test method. Six laboratories participated in the RRT, adhering to the guidelines. During tensile testing of the HTS wires at 77 K, critical current (I c) measurements were performed using a stress-based test method. This method streamlined the testing procedure by changing stress intervals from broad to narrow as the applied stress approached the I c degradation point while eliminating the need for dedicated extensometers. The EMPs of the reversible stress limit (R rev) and retention stress limit (R ret) for I c degradation were defined based on specific criteria for 99% I c0 recovery and 95% I c0 retention. Once the RRT participants reported their test results, statistical analysis tools such as ANOVA were employed to identify sources of variation and assess their magnitude in the results. The primary source of the relative standard uncertainty was the effect of inter-laboratory scattering. The RRT results are utilized to develop an international standard for evaluating EMPs of HTS wires through I c measurements under uniaxial tension at liquid nitrogen temperature. These RRT analysis results offer valuable insights into potential sources and magnitudes of measurement uncertainties, ultimately contributing to standardized test procedures for accurate and reliable EMP characterization of HTS wires.

Abstract Research consortia frequently attempt co-analysis of biomarker data from multiple sources. However, limited guidance exists on the harmonization of biomarker data, which are prone to various sources of variation. This narrative review aimed to address this gap by providing an overview of the existing methods for harmonizing biomarker data and their application. A systematic search of literature published by March 2024 was conducted using PubMed and Web of Science. Articles were included if co-analysis of individual participants data with at least one biomarker from multiple studies were reported and the biomarker harmonization methods were described. A total of 23 articles were included in the narrative review. Overall, 5 methods used for biomarker harmonization were identified: (1) calibration, (2) round robin test, (3) variable rescaling, (4) categorization, and (5) logistic regression-based method. Among these, calibration appears to be superior to other methods. To facilitate researchers in their choice of method, we suggest a roadmap for a step-wise biomarker data harmonization approach. There is a pending demand for developing standard definitions, methods, and quality criteria to assure proper harmonization practices in biomarker-based pooling initiatives.

Abstract Ten international teams participated in a second round-robin test with wake measurements behind two different types of actuator discs focusing on comparability of the experimental boundary conditions. Results show that even for such simple experiments small differences in the set-ups and inflow can lead to variations in the measurements. Nevertheless, a clear reduction in the deviations in maximum velocity deficit could be achieved for one disc compared to the first round-robin test from 2018.

SUMMARY This study presents the results of an interlaboratory test designed to evaluate the accuracy of spectral induced polarization (SIP) measurements using controlled electrical test networks. The study, conducted in Germany since 2006, involved 12 research institutes, six different impedance measurement devices and four types of electrical test networks specifically designed to evaluate phase shift errors in SIP measurements. The test networks, with impedances ranging from 100 to 150 kΩ, represent high-impedance samples with different phase characteristics, and pose the measurement challenges typical of such samples, including high contact impedances and parasitic capacitances. Four key findings emerged from the study: (1) Impedance measurements across all devices showed deviations within 1 per cent over a wide frequency range (0.001–1000 Hz); (2) phase errors remained below 1 mrad up to 100 Hz for most devices, but increased at higher frequencies due to parasitic capacitances and electromagnetic coupling effects; (3) lab-specific instruments have lower phase errors than field instruments when used in a laboratory environment, primarily due to the effects of long cables and too low input impedances of the field instruments; and (4) short cables and driven shielding technology effectively minimized parasitic capacitance and improved measurement accuracy. The study highlights the usefulness of test networks in assessing the accuracy of SIP measurements and raises awareness of the various factors influencing the quality of SIP data.

Determining the hygrothermal properties of bio-based construction products on a material scale is a major challenge in order to highlight and guarantee their performances. These data are also essential to feed models at wall and building scales for prediction and optimization of their contribution to energy consumption and user’s comfort. Among these properties, water vapor permeability is commonly measured with the dry cup method. Despite the good repeatability and reproducibility of this test when performed in one lab, one can observe a high level of discrepancy in the literature values. To address the origin of these differences and establish recommendations for the characterization of highly hygroscopic and permeable bio-based materials, an interlaboratory test is therefore necessary. In the context of the activities of the RILEM TC 275-HDB, two interlaboratory campaigns have been launched to measure the water vapor permeability of bio-aggregate based building materials by means of cup test. The analysis of the results from six participating laboratories from different countries highlighted the main sources of discrepancy, in particular the progressive saturation of the desiccant during the experiment and the incompatibility of the “steady state” criterion and the air velocity recommended by the standard ISO 12572 in the case of highly permeable materials. Despite the many sources of uncertainties, recommendations are proposed to improve the accuracy of this measurement for permeable materials such as a continuous measurement of the vapor pressure within the air layer and the measurement of the air velocity above each cup to evaluate the local interface resistance.

ABSTRACTThis article presents the results of a round robin test throughout Germany with 19 participating institutions. Corrosion product layer resistances (RL) were determined on two differently weathered pure zinc samples and a sample activated with NaOH by means of electrochemical measurement of the linear polarization resistance (LPR) using agar‐based gel electrolytes. The round robin test was organized by the Bundesanstalt für Materialforschung und ‐prüfung (BAM) in Berlin. The measurements were carried out by the participants in the period from May to July 2021. The results are summarized in this article comprising an assessment of the reproducibility and repeatability of the measurements. The methodology is suitable for distinguishing zinc surfaces after exposure to different atmospheres based on the corrosion product layer resistances (RL). In addition, possible problems in the application of the method were identified, and solutions for improving reproducibility and repeatability are discussed. The results and knowledge from the round robin test are incorporated into a new test standard (DIN 50023:2024‐07) for this measurement method.

Seed amplification assays (SAA) detect alpha-synuclein (aSYN) pathology in patient biomatrices such as cerebrospinal fluid (CSF)-potentially even before clinical manifestations. As CSF-based SAA are approaching broader use in clinical trials and research, ensuring that different laboratories obtain the same results becomes increasingly important. In this cross-laboratory, cross-aSYN-recombinant substrate and cross-protocol round-robin test, we compared SAA results from a common set of 38 CSF samples measured independently in four research laboratories of the German Center for Neurodegenerative diseases. Three laboratories (A-C) used an assay protocol adapted from Parchi's group at ISNB (Bologna, Italy); laboratory D used an assay protocol adapted from Amprion Inc. Two different manufacturers of aSYN protein were used as substrates for the SAA reaction. Qualitative results were identical in at least three of the four laboratories for 37 out of 38 samples (20 positive, 17 negative). Fleiss Kappa for all four laboratories was 0.751 (z = 12, p < 0.001). For each laboratory, agreement with laboratory A was > 92%. For the number of positive replicates, Fleiss Kappa was 0.45 for a score of zero positive replicates and 0.42 for a score of four positive replicates. The qualitative SAA results showed a high level of agreement across research laboratories, aSYN monomers, and assay protocols. Small differences between laboratories were systematic, consistent with the notion that SAA reports biologically relevant properties. These results also underline that round-robin tests can be helpful in assessing and ensuring SAA quality across laboratories.

IS-Grenoble 2024, the 5th International Symposium on Geomechanics from Micro to Macro, was organized under the auspices of Technical Committee 105 (Geomechanics from Micro to Macro) of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). The preceding symposia were held at Yamaguchi University, Japan in 2006, Tongji University, China in 2010, Cambridge University, England in 2014, and Georgia Tech, USA in 2018. As with these previous events, this symposium aimed to advance the objectives of TC 105, which are to: • promote cooperation and the exchange of information about the behavior of soil grains and granular interactions; • promote improved modeling of soil aggregates; • encourage a microstructural understanding of significant macroscopic behavior; • facilitate discussions on the use of microstructural measurements to enhance soil characterization procedures; • clarify the selection and use of continuum parameters in geotechnical engineering practice. IS-Grenoble 2024 took place under the patronage of ALERT-Geomaterials, the European association for Education, Research and Technology in Geomechanics. The symposium gathered 269 attendees, featured 96 oral and 90 poster presentations, and included 14 sessions devoted to: Numerical Modeling, Imaging, Below the micron, Innovations in Numerical Modeling, Experimental Methods, Unsaturated Materials, Dialog between experiments and modeling, Microstructure characterization, New trends in modeling, Theoretical developments, Damage/thermal behavior, Experimental Imaging, and Continuum modeling. Additionally, a plenary session was devoted to the DEM Round Robin Test organized by TC 105. List of Chair, Editors, Organizing Committee, Scientific Comittee, On-site Logistic Support and Financial Support are available in this Pdf.

Abstract The Discrete Element Method (DEM) is widely utilized to solve engineering problems. However, validating DEM analysis is still challenging except in simple cases. To address this issue, the TC105 Japanese committee conducted the round-robin test using 3D-printed particles for angle of repose experiments. To further develop the project, this study aims to quantify the impact of DEM input parameters. A series of DEM simulations were conducted using different program codes, and the sensitivity analysis was performed through four different methodologies. The results qualitatively indicated that the friction angle between particles had a dominant impact.

International inter-laboratory comparison of solar heat gain coefficient of building-integrated photovoltaic modules results of tests with or without power generation and tests with PV cell coverage ratios

A GC/FID method was developed and thoroughly validated, including a round robin test, to enable objective comparison of three lignin depolymerisation methods using the same lignosulphonate feedstock.

Cements containing calcium sulfoaluminate (CSA) have reported excellent characteristics at both early and later ages. However, there are a number of studies reporting poor durability when compared with Portland cement (PC). Durability tests are used as an indicator for service life, and thus the viability of a cement system relies on its performance in these tests. Test methods often assume a sufficient maturity based on extensively tested PC systems; however, slower hydrating binder assemblages and variable chemistries can be severely underestimated when tested at the default 28 days. For example, a belitic CSA (BCSA) cement tested at this time will fail to account for later-stage hydration products that can improve the durability of the system. Tests on the durability of BCSA cements beyond 28 days of curing are sparsely covered in the literature, although in each study the results have shown a marked improvement in durability performance – a characteristic paralleled by other slow-hydrating binders such as fly ash composite cements. The use of an equivalent cement hydration/maturity in testing protocols is proposed, which could be considered a baseline for subsequent improvements that can be made with regard to how alternative binder systems are tested. A call to action for the cement community is outlined to (a) understand what tests are actually testing at a chemical level, (b) develop a ‘cure test’ to assess maturity and (c) undertake round-robin testing.

This paper is the result of a round-robin activity run by the Technical Committee TC12, Pharma Packaging, of the International Commission on Glass (ICG). The study was motivated by a concern about the risk that the depyrogenation treatment of glass vials, when performed in an abnormal way that deviates from the usual procedure, may have a negative impact on the hydrolytic resistance of the container inner surface after filling with the drug product, for example, by increasing the release of leacheables and/or the propensity to delamination. The study was executed by using 10 mL clear type I borosilicate glass vials representing four different compositions. For the applied depyrogenation process, extreme parameters were chosen with maximum temperature up to 400°C, exposure times up to 72 hours, and different amounts of residual water inside as starting conditions. Those treated samples were tested in seven different laboratories as a round-robin test. A large amount of data was obtained, which clearly indicate that the hydrolytic resistance performance of the Type I borosilicate glass vials is not affected even by such extreme depyrogenation conditions (e.g., 400°C, 72 hours, and not perfectly dried inside). This is an important and useful result, both for glass and pharma companies, based on the 12,000 analytical data collected during the interlaboratory activity.

The urge for changes in our energy mix and in finding sustainable solutions for energy provision, pushes towards fast developments in the field of hydrogen technologies. Proton exchange membrane (PEM) water electrolysis is one of the most promising solutions for a green hydrogen production, but developments of this technology are necessary to make it cheap and feasible.To achieve this, it is necessary to have well-established and advanced characterization methods. These methods can help us understand the limitations and identify areas for improvement in cheaper, performing, and alternative materials. They can also assist us in reducing the production and activation effort of its components. By identifying the specific mechanisms or factors that limit performance or stability under certain conditions, our advanced in situ characterization techniques can provide valuable insights on durability aspects.Before utilizing advanced methods for evaluating PEM electrolysis cell, it is fundamental to accurately assess effects and changes during the tests. These changes must exceed the reproducibility error of our tests to be considered as performance variations only. To achieve this, a round robin test is conducted, which provides reproducibility error within our facility and across different institutes[ 1,2 ]. This study also offers a thorough overview of fundamental characterization, such as polarization curves and electrochemical impedance spectra (EIS).When conducting EIS measurements, it is essential to ensure that external influences are not included in the evaluation and that the discussed mechanisms belong only to the electrolysis cell response[ 3 ]. Improving our cell structure and voltage sense connection allows to uncover previously hidden processes occurring in the high frequency region of the impedance spectrum. This helps to develop reliable equivalent circuit models (ECM) that accurately represent the electrochemical, transport and electrical mechanisms taking place within an electrolysis cell.Impedance spectra serve as a valuable tool for assessing various processes occurring during electrolysis. When combined with a reference electrode, it is possible to evaluate the contribution of each electrode. It allows us to determine which electrode undergoes the most significant variations during cell activation or break-in. Additionally, EIS conducted with a reference electrode and distribution of relaxation times (DRT) can firstly provide evidence to the extent of contribution of each electrode to the overall spectra and can also specify the limiting processes associated with each electrode. The former evaluation is achieved via comparison of tests with variating operating condition in the very first hours of operation (activation or break-in). The latter study is approached via tests with different catalyst layer loadings and membrane thicknesses. These half-cell results can be used to drive developments in manufacturing of catalyst coated membrane (CCM) and fine-tuning the improvements of the electrode performance.