17 research outputs found
Life cycle analysis of reinforced concrete bridges in Baltic countries
During this paper the first part of Life Cycle Analysis based on visual inspection data of main types of
reinforced concrete bridges in Baltic countries will be introduced and discussed. In a first step, the background of
bridge management systems, visual inspections and most common bridges will be presented. During this step, an
explanation of differences and similarities of Baltics visual inspections and data processing will be introduced. In
a second step, principal component analysis with main outcomes for different Baltic countries and possible reasons
for those outcomes will be discussed. Also a comparison of principal components for similar bridges in all Baltic
countries will be shown. At the end, input for predictive models will be introduced. The main objective of this
input is to show what elements deteriorate more rapidly and due to that have an influence for Life Cycle of
reinforced concrete bridgesThe authors would like to gratefully acknowledge supporting of TU1406 – Quality specifications for roadway
bridges, standardization at a European level (BridgeSpec), a COST Action supported by EU Framework
Programme Horizon 2020.info:eu-repo/semantics/publishedVersio
RC bridge management optimisation considering condition assessment uncertainties
Decision-making in bridge management has changed considerably in the past two decades and owners are additionally considering what types of interventions to implement, but correct decisions still need certain input. In Estonia, like in many countries, bridge management is based on inventory records and condition information. The main emphasis of this investigation is on improving the regular condition assessment. More accurate nondestructive testing methods and optimised inspection scheduling are proposed, to reduce condition assessment uncertainties. A conversion matrix for translating additional assessment results to the rating scale of the current Estonian Transport Administration management system is introduced and uncertainties in the condition state are analysed probabilistically. In addition, stochastic degradation models based on existing information are investigated to help considering uncertainties as a part of the overall management process. What impact the adopting of quantitative assessment, rather than qualitative visual inspection, may have on the suggested interventions schedule is also analysed. The probabilistic characteristics of the condition profiles of the most common bridge elements are computed using Markov Chain Monte Carlo stochastic simulation. The optimisation of inspection scheduling is performed considering the uncertainty of the initial deterioration model. When a threshold value, defined by the owner, is reached, the model is updated with assessment data to maintain the level of uncertainty below that threshold. The results confirm that deviations in the degradation model and assessment results influence the bridge condition uncertainty. Likewise, times of both inspection and intervention are influenced, which will ultimately impact the overall management reliability and costs.The authors acknowledge the support of Eurostruct endorsed by the EU Framework Program Horizon 2020, the Archimedes Foundation and Professor Karl Oiger Scholarship Foundation. The publication costs of this article were covered by the Estonian Academy of Sciences
Statistical analysis of reinforced concrete bridges in Estonia
This paper introduces a possible way to use a multivariate methodology, called principal component analysis, to reduce the dimensionality of condition state database of bridge elements, collected during visual inspections. Attention is paid to the condition assessment of bridges in Estonian national roads and collected data, which plays an important role in the selection of correct statistical technique and obtaining reliable results. Additionally, detailed overview of typical road bridges and examples of collected information is provided. Statistical analysis is carried out by most natural reinforced concrete bridges in Estonia and comparison is made among different typologies. The introduced multivariate technique algorithms are presented and collated in two different formulations, with contrast on unevenness in variables and taking into account the missing data. Principal components and weighing factors, which are calculated for bridges with different typology, also have differences in results and element groups where variation is retainedTU1406 – Quality Specifications for Roadway Bridges, standardiza-
tion at a European level (BridgeSpec), a COST Action sup-
ported by EU Framework Programme Horizon 2020info:eu-repo/semantics/publishedVersio
A time-resolved proteomic and prognostic map of COVID-19
COVID-19 is highly variable in its clinical presentation, ranging from asymptomatic infection to severe organ damage and death. We characterized the time-dependent progression of the disease in 139 COVID-19 inpatients by measuring 86 accredited diagnostic parameters, such as blood cell counts and enzyme activities, as well as untargeted plasma proteomes at 687 sampling points. We report an initial spike in a systemic inflammatory response, which is gradually alleviated and followed by a protein signature indicative of tissue repair, metabolic reconstitution, and immunomodulation. We identify prognostic marker signatures for devising risk-adapted treatment strategies and use machine learning to classify therapeutic needs. We show that the machine learning models based on the proteome are transferable to an independent cohort. Our study presents a map linking routinely used clinical diagnostic parameters to plasma proteomes and their dynamics in an infectious disease
Clinical and virological characteristics of hospitalised COVID-19 patients in a German tertiary care centre during the first wave of the SARS-CoV-2 pandemic: a prospective observational study
Purpose: Adequate patient allocation is pivotal for optimal resource management in strained healthcare systems, and requires detailed knowledge of clinical and virological disease trajectories. The purpose of this work was to identify risk factors associated with need for invasive mechanical ventilation (IMV), to analyse viral kinetics in patients with and without IMV and to provide a comprehensive description of clinical course.
Methods: A cohort of 168 hospitalised adult COVID-19 patients enrolled in a prospective observational study at a large European tertiary care centre was analysed.
Results: Forty-four per cent (71/161) of patients required invasive mechanical ventilation (IMV). Shorter duration of symptoms before admission (aOR 1.22 per day less, 95% CI 1.10-1.37, p < 0.01) and history of hypertension (aOR 5.55, 95% CI 2.00-16.82, p < 0.01) were associated with need for IMV. Patients on IMV had higher maximal concentrations, slower decline rates, and longer shedding of SARS-CoV-2 than non-IMV patients (33 days, IQR 26-46.75, vs 18 days, IQR 16-46.75, respectively, p < 0.01). Median duration of hospitalisation was 9 days (IQR 6-15.5) for non-IMV and 49.5 days (IQR 36.8-82.5) for IMV patients.
Conclusions: Our results indicate a short duration of symptoms before admission as a risk factor for severe disease that merits further investigation and different viral load kinetics in severely affected patients. Median duration of hospitalisation of IMV patients was longer than described for acute respiratory distress syndrome unrelated to COVID-19
Optimeeritud seisukorra kontrolliplaani v\ue4lja t\uf6\uf6tamine t\ufc\ufcpilistele Eesti raudbetoonsildadele. Development of an Optimised Condition Assessment Plan for Common Reinforced Concrete Bridges in Estonia
Uncertainty in condition prediction of bridges based on assessment method – Case study in Estonia
In this paper the uncertainty in condition assessment based on most common assessment methods, visual inspection and non-destructive testing, is investigated. For decision-making the averaged or estimated value is suitable, but if the basis of a decision is only a subjective visual inspection, then it could lead to a wrong decision. The second most traditional assessment method is non-destructive testing (NDT), which can give reliable results, but the interpretation of measurement is needed. To investigate the errors in both evaluations, benchmarking tests were carried out in Estonia within two groups, a group of experienced inspectors and a group of unexperienced students, to show how the importance of experience affects results. To present the influence of assessment uncertainty to condition prediction curves based on continuous-time Markov model are calculated and for updating, Bayesian inference procedure is used.- (undefined
Developing case studies for implementing COST TU1406 quality control plan procedure for typical highway bridges
An extensive work was done by COST TU1406 working groups (WG) 1,2 and 3 for preparing a guidance document for Quality Control Plan (QCP) of road bridges. WG 1, 2 and 3 reports named 'Performance Indicators for Roadway Bridges', 'Performance Goals for Roadway Bridges' and 'Establishment of a quality control plan' are already published. Based on these documents and the work done to-date, a new procedure for implementing the developed guidelines for the preparation of QCP for roadway bridges was developed by WG4 members in order to unify the method used and to validate the outcomes of the developed QCP. At the first stage, a set of common highway bridge prototypes were identified including girder, frame, arch and truss bridges. A database was created where each participating country has identified local bridges for developing of the case studies. Nine out of sixty bridges where selected for the first stage of preparing an example of QCP and the case study reports were compared with an objective to validate the outcomes. A guideline document was prepared with unified instruction on how to develop the national case study per country. The typical case study includes few stages which are defined based on the work done by WG1, 2 and 3. The stages includes data collection, element identification and grouping, defining vulnerable zones, damage processes and failure modes, selecting and evaluating performance indicators (PIs) and calculating key performance indicators (KPIs), establishing demands, creating QCP scenarios and comparing them by spider diagrams. First outcomes of the prototypes case study reports are now being updated to reflect the final version of WG3 report and together with the guidelines document will be distributed among participating countries to enable the benchmarking process for the full set of bridges representing Europe common highway bridge topologies.- (undefined
Pilot Study on the Growth Inhibition by Estramustine Phosphate (Estracyt®) of Rat Mammary Tumours Sensitive and Insensitive to Oestrogen
Delayed Antibody and T-Cell Response to BNT162b2 Vaccination in the Elderly, Germany
We detected delayed and reduced antibody and T-cell responses after BNT162b2 vaccination in 71 elderly persons (median age 81 years) compared with 123 healthcare workers (median age 34 years) in Germany. These data emphasize that nonpharmaceutical interventions for coronavirus disease remain crucial and that additional immunizations for the elderly might become necessary.Peer Reviewe