30 research outputs found
The urgency of the development of CO2 capture from ambient air
CO2 capture and storage (CCS) has the potential to develop into an important tool to address climate change. Given society’s present reliance on fossil fuels, widespread adoption of CCS appears indispensable for meeting stringent climate targets. We argue that for conventional CCS to become a successful climate mitigation technology—which by necessity has to operate on a large scale—it may need to be complemented with air capture, removing CO2 directly from the atmosphere. Air capture of CO2 could act as insurance against CO2 leaking from storage and furthermore may provide an option for dealing with emissions from mobile dispersed sources such as automobiles and airplanes
Cold gas accretion in galaxies
Evidence for the accretion of cold gas in galaxies has been rapidly
accumulating in the past years. HI observations of galaxies and their
environment have brought to light new facts and phenomena which are evidence of
ongoing or recent accretion:
1) A large number of galaxies are accompanied by gas-rich dwarfs or are
surrounded by HI cloud complexes, tails and filaments. It may be regarded as
direct evidence of cold gas accretion in the local universe. It is probably the
same kind of phenomenon of material infall as the stellar streams observed in
the halos of our galaxy and M31. 2) Considerable amounts of extra-planar HI
have been found in nearby spiral galaxies. While a large fraction of this gas
is produced by galactic fountains, it is likely that a part of it is of
extragalactic origin. 3) Spirals are known to have extended and warped outer
layers of HI. It is not clear how these have formed, and how and for how long
the warps can be sustained. Gas infall has been proposed as the origin. 4) The
majority of galactic disks are lopsided in their morphology as well as in their
kinematics. Also here recent accretion has been advocated as a possible cause.
In our view, accretion takes place both through the arrival and merging of
gas-rich satellites and through gas infall from the intergalactic medium (IGM).
The infall may have observable effects on the disk such as bursts of star
formation and lopsidedness. We infer a mean ``visible'' accretion rate of cold
gas in galaxies of at least 0.2 Msol/yr. In order to reach the accretion rates
needed to sustain the observed star formation (~1 Msol/yr), additional infall
of large amounts of gas from the IGM seems to be required.Comment: To appear in Astronomy & Astrophysics Reviews. 34 pages.
Full-resolution version available at
http://www.astron.nl/~oosterlo/accretionRevie
The activation of eco-driving mental models: can text messages prime drivers to use their existing knowledge and skills?
Eco-driving campaigns have traditionally assumed that drivers lack the necessary knowledge and skills and that this is something that needs rectifying. Therefore, many support systems have been designed to closely guide drivers and fine-tune their proficiency. However, research suggests that drivers already possess a substantial amount of the necessary knowledge and skills regarding eco-driving. In previous studies, participants used these effectively when they were explicitly asked to drive fuel-efficiently. In contrast, they used their safe driving skills when they were instructed to drive as they would normally. Hence, it is assumed that many drivers choose not to engage purposefully in eco-driving in their everyday lives. The aim of the current study was to investigate the effect of simple, periodic text messages (nine messages in 2 weeks) on drivers’ eco- and safe driving performance. It was hypothesised that provision of eco-driving primes and advice would encourage the activation of their eco-driving mental models and that comparable safety primes increase driving safety. For this purpose, a driving simulator experiment was conducted. All participants performed a pre-test drive and were then randomly divided into four groups, which received different interventions. For a period of 2 weeks, one group received text messages with eco-driving primes and another group received safety primes. A third group received advice messages on how to eco-drive. The fourth group were instructed by the experimenter to drive fuel-efficiently, immediately before driving, with no text message intervention. A post-test drive measured behavioural changes in scenarios deemed relevant to eco- and safe driving. The results suggest that the eco-driving prime and advice text messages did not have the desired effect. In comparison, asking drivers to drive fuel-efficiently led to eco-driving behaviours. These outcomes demonstrate the difficulty in changing ingrained habits. Future research is needed to strengthen such messages or activate existing knowledge and skills in other ways, so driver behaviour can be changed in cost-efficient ways
Programmeerbare freesmachine geen grote hindernis voor L.T.S.-ers
Een groep L.T.S.-ers, bekend met werken op een conventionele freesbank, krijgt de
opdracht een programmeerbare freesbank te bedienen en alle voorbereidende werkzaamheden te verrichten, dit als experiment. Er blijkt onder meer uit dat ze sneller leren dan verwacht werd en dat het overgrote deel van de groep liever met de nieuwe dan
met de conventionele techniek werkt
The Dutch IOR approach to organisational design : an alternative to business process re-engineering
This paper presents the current Dutchsociotechnical design approach to integralorganizational renewal in a contextual way. Both itsdesign theory and intervention processes are reviewedand some aggregated empirical evidence is presented. Next, thepaper compares the ideas developed in the Dutch approachto those presented in its American, Scandinavian, andAustralian counterparts. It is concluded that, at a meta-level, they all share the ideal ofparticipative democracy, while at the conceptual level,these distinctive approaches appear quite incompatible.Notwithstanding substantial diversity, it is presumed these approaches can be seen as localmanifestations of a single sociotechnicalparadigm
Design or development? Beyond the LP-STS debate; inputs from a Volvo truck case
In this paper, we will show that the debate between advocates of Lean production and the socio-technical approach has concentrated too much on the design aspect of the production structure, while neglecting the development aspect of teamwork. This paper addresses the question whether it is production design or team development that explains business performance and the quality of working life. The data are taken from four departments of the Volvo truck plant in Umea (Sweden) that is redesigning from socio-technical based assembly to line-assembly. We conclude that good design of the production structure is necessary, but not sufficient for good performance; team development is just as important, although it requires a favorable context
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The urgency of the development of CO2 capture from ambient air: Supporting information
CO2 capture and storage (CCS) has the potential to develop into an important tool to address climate change. Given society’s present reliance on fossil fuels, widespread adoption of CCS appears indispensable for meeting stringent climate targets. We argue that for conventional CCS to become a successful climate mitigation technology—which by necessity has to operate on a large scale—it may need to be complemented with air capture, removing CO2 directly from the atmosphere. Air capture of CO2 could act as insurance against CO2 leaking from storage and furthermore may provide an option for dealing with emissions from mobile dispersed sources such as automobiles and airplanes