Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Constraint solving for direct manipulation of features

In current commercial feature modeling systems, support for direct manipulation of features is not commonly available. This is partly due to the strong reliance of such systems on constraints, but also to the lack of speed of current constraint solvers. In this paper, an approach to the optimization of geometric constraint solving for direct manipulation of feature dimensions, orientation, and position is described. Details are provided on how this approach was successfully implemented in the Spiff feature modeling system.MediamaticsIndustrial Design Engineerin

Ram-air kite airfoil and reinforcements optimization for airborne wind energy applications

We present a multidisciplinary design optimization method for the profile and structural reinforcement layout of a ram‐air kite rib. The aim is to minimize the structural elastic energy and to maximize the traction power of a ram‐air kite used for airborne wind energy generation. Because of the large deformations occurring during flight, a fluid‐structure interaction (FSI) routine is included in the optimization, which determines the actual deformed rib geometry and its corresponding aerodynamic characteristics. A qualitative comparison between FSI inclusion and exclusion in the optimization is given. Discrepancies in airfoil profile and structural layout are observed.Wind Energ

Probabilistic Design Space Mapping: Application to Airfoil Design for HAWT

This work presents an airfoil probabilistic design methodology for wind energy applications, using an analytical approach to estimate the angle-of-attack fluctuations produced by non-uniformities in the incoming wind field. The contemplated wind speed perturbations include wind shear, yaw misalignment and atmospheric turbulence, and several combinations of the perturbation sources are considered. A probabilistic design space mapping is carried out to evaluate which wind conditions occur more often in practice and how likely each specific combination of perturbation sources is to occur, for both an onshore and offshore scenario. The proposed probabilistic method and specifically the level of angle-of-attack fluctuations is verified by employing the aero-elastic simulation tool FAST for each case. Finally, the probabilistic approach is used to design airfoils sections employing the genetic multi-objective airfoil optimization tool Optiflow, where the probability of angle of attack fluctuations for a given scenario is used to prescribe the operational angle of attack range over which the airfoil performance is relevant. Results of the airfoil optimization for a 24% thick section are presented, illustrating the trends in foil geometry and aerodynamic performance for three different possible optimization objective functions. Wind Energ

Unit exergy cost and specific CO₂ emissions of the electricity generation in the Netherlands

Exergy and environmental analyses have been developed to determine the performance of the electricity generation in the Dutch mix. A comparative assessment of diverse technological routes, including fossil and renewable energy resources consumption, is carried out in terms of the exergy costs and specific CO2 emissions. Hence, an exergoeconomy methodology is used to properly allocate the renewable and non-renewable exergy costs and specific CO2 emissions among the various products of the polygeneration energy systems. By using a suitable methodology, the distribution of irreversibility throughout the different steps of the energy conversion processes of the Dutch electricity mix is characterized in the light of the Second Law of Thermodynamics. The results may help to propose performance indicators that support the Dutch government and research institutions. To identify sustainable energy planning strategies and fairly comparing electricity generation and end-use processing stages with other types of energy resources, such as fuels used in transportation, residential and industrial sectors. In brief, the weighted average of the renewable and non-renewable unit exergy costs and the specific CO2 emissions of the electricity generated in each route of the Dutch mix is calculated and compared to another electricity mix with a higher share of renewable energy resources. The weighted average renewable and non-renewable unit exergy costs of the electricity generated in the Netherlands are calculated as cR = 0.8375 kJ/kJE/W and cNR = 1.7180 kJ/kJE/W, respectively (cR/cNR= 0.49). Furthermore, the specific CO2 emissions in the Dutch electricity generation achieve 373.21 gCO2/kWhE/W.BT/Biotechnology and Societ

Modern office related determinants of dry eye complaints: The OFFICAIR study

Architecture and The Built Environmen

Enhanced Fatigue Life of Old Metallic Bridges - Application of Preloaded Injection Bolts

There is a significant number of old metallic bridges with high levels of structural degradation due to their long service period. Fatigue problems are especially important in these structures since the majority of them were not designed taking into account this phenomenon. Several investigations showed that riveted joints are critical details since several fatigue cracks were found in these joints. In this sense, strengthening methodologies need to be studied. The strategy that has been considered a good solution is the implementation of injection bolts to replace faulty rivets. The structural performance of injection bolts has been demonstrated essentially under quasi-static conditions presenting good results. This paper intends to contribute to the scientific knowledge regarding the fatigue behavior of connections with preloaded injection bolts in the context of a bridge strengthening scenario. An experimental investigation was conducted to compare the fatigue performance of connections with preloaded injection bolts and preloaded standard bolts. Single and double shear connections were tested. New S–N design curves were proposed based on a statistical analysis of the results and compared with the S–N curves proposed in EC3-1–9. The obtained results showed that the use of injection bolts lead to lower scatter and improvement of fatigue life. It was verified that the Eurocode 3 is not able to represent the fatigue strength of connections whose performance is influenced by old metallic materials. Additionally, the fatigue behavior of these connections was assessed by numerical analysis. The relevance of the fatigue crack initiation was evident.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Steel & Composite Structure

Austenite carbon enrichment and decomposition during quenching and tempering of high silicon high carbon bearing steel

The addition of Si to steels is a well stablished method to delay cementite precipitation, allowing for carbon partitioning from martensite to retained austenite during tempering. It has been argued that carbon enrichment and stabilization of austenite leads to increased ductility and toughness. This has been the main motivation for the development of novel heat treatments, such as quenching and partitioning. High carbon steels can also benefit from improved ductility provided by the presence of stabilized retained austenite. However, the process of carbon partitioning is less understood due to the increased tendency for competitive carbide formation with increasing carbon content. The present work investigates the austenite carbon partitioning and austenite decomposition phenomena in a modified 1.82 wt.% Si hypereutectoid bearing steel during tempering. Dilatometry, in-situ and ex-situ synchrotron X-ray diffraction, 3D atom probe tomography, scanning electron microscopy, and hardness measurements were used. The results are discussed based on different equilibrium states between α' and carbides. It was found that carbon partitioning towards retained austenite occurs for several minutes without significant phase decomposition at temperatures lower than 300 °C. A transition temperature between prevalent austenite carbon enrichment and austenite decomposition occurs at 350 °C. Secondary cementite precipitation inside martensite, and at the α'/γ interfaces, is observed during tempering at temperatures above 400 °C. Results from constrained carbon equilibrium modeling with carbide presence indicate that homogeneously dispersed spheroidized primary cementite has little influence in the carbon partitioning phenomenon.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Maria Santofimia Navarr

Subsidence of organic dredged sediments in an upland deposit in Wormer- en Jisperveld: North Holland, the Netherlands

Land subsidence in low-lying peatlands can be caused by shrinkage and organic matter oxidation. When these areas have networks of ditches and canals for drainage purposes, the sediments that accumulate in the waterways can be used to reverse the process of land subsidence. The objective of this study is to understand how dredged sediments can be used to reverse the process of land subsidence by analysing the contribution of shrinkage and organic matter mineralization to the subsidence observed in an upland deposit. A deposit of dredged sediments in the Wormer- en Jisperveld—North Holland, the Netherlands—was characterized during 17 months in terms of subsidence of the sediments, subsidence of the soil underlying the deposit, geotechnical water content, organic matter content, type of organic matter and nutrients. The deposit was filled to a height of 195 cm, and after 17 months, the subsidence of the sediments was 88 cm. In addition, a subsidence of 19.5 cm of the underlying soil was observed. Subsidence could be attributed to shrinkage since no significant changes in the organic matter content and total organic carbon were observed. The type of organic matter changed in the direction of humification until winter 2014, stabilized from winter 2014 to spring 2015 and changed in the direction of mineralization after the spring of 2015. Subsidence of dredged sediments in upland deposits is caused by shrinkage during the first 17 months. The solution of spreading thinner layers of sediments over the land to decrease the subsidence rates should be explored since the pressure of the deposit on the underlying soil caused an extra subsidence of 19.5 cm.Geo-engineerin

Office characteristics and dry eye complaints in European workers: The OFFICAIR study

Objectives Ocular discomfort is a prevalent health complaint in offices. It is hypothesized that, in addition to individual and occupational factors, the buildings' indoor environment may affect eye complaints. However, insight in potential building-related causal factors, needed to allow development of effective prevention strategies in building design, operation and maintenance is limited. This study aimed to investigate the relations between modern office building characteristics and dry eye complaints. Methods Comprehensive characteristics of 167 office buildings in eight European countries, were linked to questionnaire data from 7441 office workers. Multilevel modeling was applied to explore relations between building characteristics and self-reported dry eye complaints, in a cross-sectional study. Results Among office workers investigated, 34% declared dry eye complaints during the past four weeks. Majority of workers (91.2%) experiencing these symptoms, reported improvement on days away from the office. After full adjustment, the regression model revealed a significant increased risk for: proximity (<100 m) to potential sources of outdoor air pollution (OR: 1.41, 95% CI: 1.06–1.88), absence of operable windows (OR: 1.70, 95% CI: 1.34–2.16), portable humidifiers in the offices (OR: 1.58, 95% CI: 1.18–2.11), exposed concrete and/or plaster (OR: 1.29, 95% CI 1.02–1.62) and dispersion and/or emulsion paint as wall covering in offices (OR: 1.20, 95% CI: 1.01–1.41). A negative association was found for cleaning surfaces at least once per week (OR: 0.75, 95% CI: 0.61–0.91). Conclusions Building characteristics were associated with dry eye complaints of office workers. Focused studies are recommended to investigate underlying causes to prevent these symptoms.Architectural Engineering +TechnologyBuilding Physic