Use of life cycle assessments in the construction sector : critical review

A life cycle assessment (LCA) is an internationally accepted and useful tool to assess the environmental impact of products. In this paper, the use of LCA in the construction sector has been critically analyzed. The analysis is based on specific literature cases and different standards and frameworks. As an example, a detailed comparison of four LCA studies for structural concrete is presented. LCA is one of the most promising techniques for an ecological design of products. However, in order to appeal to the benefits of LCA, it is important to know how to use LCA properly. From the review in this article it becomes clear that the LCA research is still in a fragmented state, due to the existence of various unspecific guidelines and different interpretations of those guidelines. Since for example the international standards on LCA, ISO 14040/44, only provide a global framework, and no exact technique to calculate environmental impacts, it is possible to create an LCA with different boundary conditions. Hence, a valuable comparison between distinct LCAs is difficult. Comparisons should thus thoughtfully be performed, taking into account all information about the LCAs under study. When this background information is communicated transparently, LCAs can be interpreted correctly

Outcome in patients perceived as receiving excessive care across different ethical climates: a prospective study in 68 intensive care units in Europe and the USA

Purpose: Whether the quality of the ethical climate in the intensive care unit (ICU) improves the identification of patients receiving excessive care and affects patient outcomes is unknown. Methods: In this prospective observational study, perceptions of excessive care (PECs) by clinicians working in 68 ICUs in Europe and the USA were collected daily during a 28-day period. The quality of the ethical climate in the ICUs was assessed via a validated questionnaire. We compared the combined endpoint (death, not at home or poor quality of life at 1 year) of patients with PECs and the time from PECs until written treatment-limitation decisions (TLDs) and death across the four climates defined via cluster analysis. Results: Of the 4747 eligible clinicians, 2992 (63%) evaluated the ethical climate in their ICU. Of the 321 and 623 patients not admitted for monitoring only in ICUs with a good (n = 12, 18%) and poor (n = 24, 35%) climate, 36 (11%) and 74 (12%), respectively were identified with PECs by at least two clinicians. Of the 35 and 71 identified patients with an available combined endpoint, 100% (95% CI 90.0–1.00) and 85.9% (75.4–92.0) (P = 0.02) attained that endpoint. The risk of death (HR 1.88, 95% CI 1.20–2.92) or receiving a written TLD (HR 2.32, CI 1.11–4.85) in patients with PECs by at least two clinicians was higher in ICUs with a good climate than in those with a poor one. The differences between ICUs with an average climate, with (n = 12, 18%) or without (n = 20, 29%) nursing involvement at the end of life, and ICUs with a poor climate were less obvious but still in favour of the former. Conclusion: Enhancing the quality of the ethical climate in the ICU may improve both the identification of patients receiving excessive care and the decision-making process at the end of life

The Comet Interceptor Mission

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms−1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule

Cognitive biases in the judgment of ethically charged contexts: numerosity and solitaire illusion

The objective of this paper is to investigate whether cognitive biases such as the numerosity effect (i.e. separate units are perceived as more numerous than one large entity) and solitaire illusion (i.e. a small number of clusters containing many entities is perceived as more numerous than a large number of clusters containing few entities) influence the judgment of ethically charged scenarios. We find that the numerosity effect holds for the ethical evaluation of most ethically charged situations (with the exception of charity), yet the opposite is true for the estimation of the impact (negative or positive) of such situations. The same cannot be asserted with respect to solitaire illusion, which exhibits inconsistent results. These results hold important implications for the framing of ethically charged events

Comparative material-based life cycle analysis of structural beam-floor systems

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Green concrete: optimization of high-strength concrete based on LCA

The construction industry is accountable for about 50 percent of the global resource consumption. Within this, traditional concrete is one of the products with a manufacturing process that has a relatively large impact on the environment. As a result of the rising awareness regarding sustainability, concrete suppliers, product manufacturers, and building contractors are concerned about which environmental impact their product has. Based on a life cycle assessment (LCA) it is possible to analyze the different stages in the life cycle of structures and to evaluate the respective impacts. Such a study is presented here for a producer of high-strength concrete building materials, applying a cradle-to-gate approach with options. Specific company data were combined with general input from databases, and a functional unit of 1m³ was adopted to be able to compare the different results. Based on this, it was determined that whereas the reinforcing and prestressing steel and the cement dominate the impact contributions, other factors such as transport by road, maintenance, aggregates, fabrication and concrete waste production during fabrication are non-negligible. A further impact study shows that several adaptions can potentially reduce the impact on the environment with 20 to 30 percent, depending on the assessment method used