This paper aims to analyze the behavior of experimentally tested unreinforced masonry walls subjected to in-plane loading. Monotonic load analyses are conducted using FEM and AEM modeling approaches. The models presented here are based on the assumption of both unit and mortar joints modeled as solid elements, which behave nonlinearly. Therefore, the damages occur along the mortar and brick in the analyses. The FEM analysis is carried out by using LS-DYNA, and the AEM analysis is carried out by using ELS (Extreme Loading for Structures). Experimental studies of a masonry wall in-plane loading conditions are used for verification against numerical models. Analysis of the tests performed on masonry shear walls by Raijmakers and Vermeltfoort [1] within the CUR [2] project is carried out. The presented analyses methods can be applied to other unit and mortar compositions. Computational results from this study provide a monotonic load-deformation curve, which then is compared to the envelope of the horizontal load-deformation curves that are experimentally obtained. The agreement of each method with the experimental results, in terms of strength, stiffness and ductility, as well as the predicted damage mechanisms, are discussed.
DOCUMENT
Plasmid-mediated dissemination of antibiotic resistance among fecal Enterobacteriaceae in natural ecosystems may contribute to the persistence of antibiotic resistance genes in anthropogenically impacted environments. Plasmid transfer frequencies measured under laboratory conditions might lead to overestimation of plasmid transfer potential in natural ecosystems. This study assessed differences in the conjugative transfer of an IncP-1 (pKJK5) plasmid to three natural Escherichia coli strains carrying extended-spectrum beta-lactamases, by filter mating. Matings were performed under optimal laboratory conditions (rich LB medium and 37°C) and environmentally relevant temperatures (25, 15 and 9°C) or nutrient regimes mimicking environmental conditions and limitations (synthetic wastewater and soil extract). Under optimal nutrient conditions and temperature, two recipients yielded high transfer frequencies (5 × 10–1) while the conjugation frequency of the third strain was 1000-fold lower. Decreasing mating temperatures to psychrophilic ranges led to lower transfer frequencies, albeit all three strains conjugated under all the tested temperatures. Low nutritive media caused significant decreases in transconjugants (−3 logs for synthetic wastewater; −6 logs for soil extract), where only one of the strains was able to produce detectable transconjugants. Collectively, this study highlights that despite less-than-optimal conditions, fecal organisms may transfer plasmids in the environment, but the transfer of pKJK5 between microorganisms is limited mainly by low nutrient conditions.
MULTIFILE
Manure application can spread antimicrobial resistance (AMR) from manure to soil and surface water. This study evaluated the role of the soil texture on the dynamics of antimicrobial resistance genes (ARGs) in soils and surrounding surface waters. Six dairy farms with distinct soil textures (clay, sand, and peat) were sampled at different time points after the application of manure, and three representative ARGs sul1, erm(B), and tet(W) were quantified with qPCR. Manuring initially increased levels of erm(B) by 1.5 ± 0.5 log copies/kg of soil and tet(W) by 0.8 ± 0.4 log copies/kg across soil textures, after which levels gradually declined. In surface waters from clay environments, regardless of the ARG, the gene levels initially increased by 2.6 ± 1.6 log copies/L, after which levels gradually declined. The gene decay in soils was strongly dependent on the type of ARG (erm(B) < tet(W) < sul1; half-lives of 7, 11, and 75 days, respectively), while in water, the decay was primarily dependent on the soil texture adjacent to the sampled surface water (clay < peat < sand; half-lives of 2, 6, and 10 days, respectively). Finally, recovery of ARG levels was predicted after 29–42 days. The results thus showed that there was not a complete restoration of ARGs in soils between rounds of manure application. In conclusion, this study demonstrates that rather than showing similar dynamics of decay, factors such as the type of ARG and soil texture drive the ARG persistence in the environment.
MULTIFILE
In de recente open brief van de creatieve industrie aan de informateur worden overheden opgeroepen samen met onderzoekers en de praktijk te experimenteren om hun digitale transformatie te laten slagen. Deze KIEM-aanvraag voorziet in deze behoefte. Het project heeft als doel in co-creatie met praktijkpartners voor de gemeenten Utrecht en Overbetuwe een data-gedreven segmentatiemodel en bijbehorend communicatie- en participatie-instrument te ontwikkelen die deze gemeenten in staat stelt om innovatie op het gebied van burger- en buurtparticipatie aan te jagen. Dit gebeurt in living labs, waarbij hogescholen en praktijkpartners samen experimenteren met nieuwe vormen van vraaggestuurde (digitale) communicatie. Centraal in het experimenteren staan 14 (concept) ‘betrokkenheidsprofielen’, die in de living labs (1) getoetst worden, en (2) waarvoor een concretiseringsslag gemaakt wordt richting strategische en tactische communicatie. In ieder living lab zullen enkele profielen centraal staan. De onderzoekspartners in het consortium, dat naast de gemeenten Utrecht en Overbetuwe bestaat uit de Hogeschool van Arnhem en Nijmegen, de Hogeschool Utrecht en Citisens (onderdeel van Necker van Naem, een onderzoek- en adviesbureau in de publieke sector), hebben de gezamenlijke ambitie na deze KIEM-aanvraag een vervolgaanvraag in te dienen, met meer Nederlandse gemeenten. In deze nieuwe aanvraag zullen andere (concept) betrokkenheidsprofielen getoetst en geconcretiseerd worden, met als uiteindelijke doel het data-gedreven segmentatiemodel voor de 14 profielen volledig te valideren. Beoogde uitkomsten van het project, dat een looptijd heeft van 1 jaar, zijn (1) het eerder genoemde communicatie- en participatie-instrument voor beide participerende gemeenten, (2) een blogserie, en (3) een openbare afsluitende bijeenkomst waarin de resultaten van het onderzoek en een doorkijk naar de toekomst gedeeld zullen worden.
In Gelderland at industriepark Kleefsewaard, a prominent knowledge hub for hydrogen technology has been developed, featuring key industry players and research groups contributing to innovative and cost-effective hydrogen technologies. However, the region faces a challenge in the lack of available test equipment for hydrogen innovations. In Anion Exchange Membrane (AEM) technology, a route to follow is to create hydrogen more efficiently with stacks that can operate under high pressure (50 bar – 200 bar). This results in compact hydrogen storage. Research must be done to understand crossover effects which become more apparent at these high pressure conditions. The overall goal is to design a Balanced of Plant (BOP) system, incorporating Process Flow Diagram (PFD) and Piping & Instrumentation Diagram (P&ID) elements, alongside hydrogen purification systems and gas-liquid separators, for a test setup operating AEM stacks at 200 bar. De Nooij Stainless contributes by designing and fabricating a gas liquid separator, addressing challenges such as compatibility, elevated temperatures, and hydrogen safety. ON2Quest collaborates in supporting the design of a hydrogen purification system and the Balance of Plant (BoP), ensuring flexibility for testing future stacks and hydrogen purification components. HyET E-Trol specializes in high pressure (up to 200 bar) AEM electrolyser stacks and is responsible for providing problem statements and engineering challenges related to the (Balanced of Plant) BoP of AEM systems, and contributes in solving them. Subsequent projects will feature test sequences centered on other stacks, allowing for testing stacks from other companies. The resulting framework will provide a foundation for ongoing advancements, with contributions from each partner playing a crucial role in achieving the project's goals.
This Professional Doctorate (PD) research focuses on optimizing the intermittency of CO₂-free hydrogen production using Proton Exchange Membrane (PEM) and Anion Exchange Membrane (AEM) electrolysis. The project addresses challenges arising from fluctuating renewable energy inputs, which impact system efficiency, degradation, and overall cost-effectiveness. The study aims to develop innovative control strategies and system optimizations to mitigate efficiency losses and extend the electrolyzer lifespan. By integrating dynamic modeling, lab-scale testing at HAN University’s H2Lab, and real-world validation with industry partners (Fluidwell and HyET E-Trol), the project seeks to enhance electrolyzer performance under intermittent conditions. Key areas of investigation include minimizing start-up and shutdown losses, reducing degradation effects, and optimizing power allocation for improved economic viability. Beyond technological advancements, the research contributes to workforce development by integrating new knowledge into educational programs, bridging the gap between research, industry, and education. It supports the broader transition to a CO₂-free energy system by ensuring professionals are equipped with the necessary skills. Aligned with national and European sustainability goals, the project promotes decentralized hydrogen production and strengthens the link between academia and industry. Through a combination of theoretical modeling, experimental validation, and industrial collaboration, this research aims to lower the cost of green hydrogen and accelerate its large-scale adoption.
