Cowi (Denmark)

Assessment of the pathogenic potential (virulence and toxicity) in non-pathogenic bacterial species is a challenge as it relies on methods developed for assessment of species known to be pathogenic. Here, we have applied and evaluated some of these methods on industrially relevant bacteria to differentiate between 'true' virulence factors applying only to pathogens and niche factors being defined as promoting colonization and survival rather than pathogenicity and as being present also in non-pathogenic bacteria. We examined the pathogenicity of 49 strains from 9 industrially relevant bacterial species (Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus delbrueckii, Lacticaseibacillus rhamnosus, Limosilactobacillus fermentum, Latilactobacillus curvatus, Ligilactobacillus salivarius, Staphylococcus carnosus and Staphylococcus xylosus), including 14 clinical isolates of the same species, through genomic screening and phenotypically through assays established for pathogenic bacteria. The genomes were screened against the Virulence Factor Database (VFDB), and thresholds (>80% nucleotide or protein identity, >70% coverage) provided by the European Food Safety Authority (EFSA) were adopted to differentiate between genes of potential concern and genes of no concern. Core genome analysis was performed to determine whether the clinical isolates were phylogenetically related to the industrial isolates. The genotypic assessment did not reveal the presence of true virulence factors in the examined strains, and in the core genome analysis, the clinical isolates could not be distinguished from the industrial strains. Furthermore, cytotoxicity toward Vero cells, negative impact on Caco-2 cell viability and haemolytic activity on blood agar plates were examined, and none of the tested strains exhibited any activity in these assays. Overall, the results suggest that VFDB screening with the EFSA thresholds can be used to differentiate between true virulence factors and niche factors. Furthermore, the use of phenotypic assays supports the genotypic assessment, albeit expert knowledge is required to interpret the results.

Abstract There is no accurate and generally accepted method for modeling solid reinforced concrete structures with complex triaxial stress states. Recently, however, finite element limit analysis (FELA) has been proposed as such a method. FELA is a load optimization technique based on the theorems of rigid plasticity, here applied using the lower bound theorem, which aims to maximize the load carried by a structure subject to the constraints of stress equilibrium and the yield condition of the materials. The objective of this study is to show the capability of a FELA framework based on solid modeling in predicting the load bearing capacity of reinforced concrete pile caps. This is done by considering an experimental database consisting of pile caps supported by four piles. The pile caps in the database stem from 11 different sources and have different shapes, sizes, and reinforcement layouts. The capacity obtained from the FELA calculations shows a good correlation with the reported capacity from the experiments. Furthermore, when comparing the ratio of the calculated capacity to the reported capacity, it is found that the scatter of the observations is largest for a reported shear failure, while the scatter is small when the failure is governed by yielding of the reinforcement. It is concluded that the model is able to safely predict the capacity of the pile caps.

<strong class="journal-contentHeaderColor">Abstract.</strong> Growing Offshore Wind Turbines (OWTs) are increasingly vulnerable to fatigue damage, motivating stress monitoring at critical, often inaccessible locations, for asset integrity management and life-extension. Virtual sensing methodologies, such as multi-band Modal Decomposition and Expansion (MDE), offer a solution by extrapolating measurements from sensors at accessible locations. However, existing MDE studies often model the Rotor-Nacelle-Assembly (RNA) as a lumped mass inertia, thereby ignoring blade flexibility and rotor operation. This leads to errors in estimated strains or stresses, particularly close to the tower top, where blade vibrations significantly influence the structural response. Moreover, neglecting blade flexibility can also lead to inaccurate tower mode shapes, causing errors not limited to the tower top. The present paper investigates the errors of multi-band MDE estimates resulting from modelling the RNA as a lumped inertia. To this end, a dataset of HAWC2 simulations covering the Fatigue Limit State (FLS) design life of the IEA Wind 15-Megawatt Offshore Reference Wind Turbine with a monopile foundation (IEA 15-MW RWT) is considered. Utilizing this dataset, multi-band MDE is used to estimate section moments along the entire supporting structure of the IEA 15-MW RWT. These estimates are compared against the true response extracted from the dataset in terms of Damage Equivalent Loads (DELs) and Damage Equivalent Stresses (DESs) combined for the individual Design Load Cases (DLCs). Additionally, the error of the MDE estimates is assessed for individual 10-minute time series from the same dataset. Based on the combined DELs and DESs, it is concluded that the MDE used in the present work performs well for long-term estimates, except in the area around the tower top, where blade vibrations and 3P effects significantly impact the quality of the estimates. It is shown that the MDE errors for the individual 10-minute time series are generally in the range of. However, the error is as high as in the tower top, where the impact from the lumped inertia RNA model is large. Finally, the error of the MDE estimates exhibits wind speed dependency. This underlines the inherent limitation in the MDE, which assumes a linear and time-invariant response and thus cannot capture the temporal variability of the dynamic model due to changing operational and environmental conditions. In conclusion, multi-band MDE provides accurate estimates of section moments across most of the IEA 15-MW RWT supporting structure, though without capturing the effects of operational and environmental variability. Furthermore, improvements are necessary to effectively capture the effects of blade flexibility, particularly near the tower top.

Living Breakwaters is an innovative nature-based coastal infrastructure project designed to reduce and mitigate erosion and damage from storm waves, improve the ecosystem health of Raritan Bay, and encourage stewardship of our nearshore waters, enhancing people’s experience of the southern shoreline of Staten Island.

This research assesses and compares the seismic performance of four reinforced concrete columns subjected to lateral cyclic loading. Two columns were reinforced with ASTM A955 Grade 75 reinforcement, whereas the other two were reinforced with CSA G30.18 400W reinforcement, each with aspect ratios of 3 and 6. This study aims to lay the foundation for future performance-based seismic design guidelines for reinforced concrete (RC) bridge piers reinforced with stainless steel rebars. This is achieved by delving into various aspects of seismic behavior, including hysteretic response, column ductility, energy dissipation, plastic hinge length, and performance damage states. The ASTM A955 Grade 75 columns showed similar hysteretic behavior to the CSA G30.18 400W columns up to 7.5% drift and ductility level of 4. At failure (20% strength degradation), the stainless steel columns demonstrated comparable drift ratios, albeit a lower overall ductility capacity due to their higher displacement at yield. In terms of energy dissipation, the CSA G30.18 columns showed higher energy dissipation at similar drift levels and at failure compared to the ASTM A955 Grade 75 columns. Evaluation of plastic hinge length prediction models revealed higher discrepancies for columns reinforced with stainless steel reinforcement, and further investigation is warranted. Also, performance damage states, including concrete cracking, cover spalling, stirrup yielding, bar buckling, and bar fracture, showcased material-specific responses and unveiled critical insights about the applicability of code strain limitations and prediction models for ASTM A955 Grade 75 reinforcement. The research emphasizes the need for tailored approaches based on the distinct behavior of stainless steel.

Here we present data from two studies, both of which had the purpose of investigating the potential of using electroencephalograms measured from the ear (’ear-EEG’) for sleep monitoring in a home environment. In total, 320 nights were recorded. All nights were recorded with ear-EEG, and some were also recorded using scalp-EEG and/or wristworn actigraphy. All subjects were recorded multiple times. To our knowledge, this is the most extensive open access data set available for mobile EEG development, and possibly also the best open access dataset for studying repeated sleep monitoring on individuals. We describe the details of each data set, including data quality measures, and compare the sleep scoring performance to a previously published dataset.

&lt;p&gt;Ship collisions with bridges and other fixed infrastructure can be attributed to various types of ab- errancy, i.e. various causes for a vessel to deviate from its intended route and various resulting col- lision trajectories. Holistic approaches aim to create a simple model of aberrant behaviour, whereas. scenario-based approaches create an array of deviation trajectories. Regardless of the approach, it is both a philosophical and a practical challenge to calibrate the models, as observations of aberrant vessels are too rare and thus often insufficient for calibration. As a consequence, statistics from non- aberrant movements combined with engineering judgment are often used instead. This paper gives an overview of the different methodologies, their strengths and challenges.&lt;/p&gt;

Repair of concrete structures must be considered very carefully and preferably only be used if the cause of the damage has been clarified and will be remedied. Furthermore, the repair must be able to achieve a durability that is comparable to the remaining life of the surrounding structure. Correct repair and possibly supplementary protection of concrete structures is in many cases a more sustainable and cheaper solution than replacing the same structure. By March 2024, the authorities responsible for the management and maintenance of infrastructures in Denmark publish new General Work Specifications for the repair and protection of concrete structures. The paper summarizes how the common European standards for repair and protection of concrete structures (the EN 1504 series) have been and will be further implemented in Denmark. Examples from the specifications are shown. The approach is applicable for other countries as well. To apply the standards the presumed methodology must be used. It is presupposed that personnel have the necessary skills and adequate equipment and resources to design, specify and execute the work in accordance with the relevant part of EN 1504 and the requirements of the project specification. The skill levels for each function in the value chain of a repair project has been defined in the standard DS 2425. A training programme has been defined as well and training lectures are being planned. The paper gives short illustrative examples of typical obstacles that can be met by the inspector of concrete structure to be repaired, the person in charge of the elucidation of defining the cause of damage and hence the extend, the person in charge of the design, the person in charge of pricing the works, the person in charge of the supervision and the person in charge of the execution.