1,197 research outputs found
Continuous-feed nanocasting process for the synthesis of bismuth nanowire composites
We present a novel, continuous-feed nanocasting procedure for the synthesis
of bismuth nanowire structures embedded in the pores of a mesoporous silica
template. The immobilization of a bismuth salt inside the silica template from
a diluted metal salt solution yields a sufficiently high loading to obtain
electrically conducting bulk nanowire composite samples after reduction and
sintering the nanocomposite powders. Electrical resistivity measurements of
sintered bismuth nanowires embedded in the silica template reveal
size-quantization effects
Designing on the road; Exploring the who, where and why of individual mobility devices
The aim of this study is to support designers in dealing with the variety of situations in which product are used, so-called dynamic and diverse use situations (DDUS). Dealing with varying use situations in the design process is difficult because it is hard to predict the situations in which a product will be used, to anticipate what will happen when the product encounters those situations and to generate solutions for conflicting requirements. A retrospective case study of three design projects in practice furthermore showed that knowledge of DDUS often remains implicit and is not shared between members of a product development team. We therefore developed a set of guidelines to support designers and design teams when dealing with DDUS in the design process. The basic principle of the guidelines is that existing design activities are used to create and apply an explicit 'frame of reference of product use' which makes DDUS and their relation to use issues explicit. In this paper we explain these guidelines and show its application to the design of an individual mobility device
4D measures of migration as a safety prediction of hip and knee implants: advances in evaluating implant fixation
Improving implant longevity is an eminent challenge in joint replacement surgery with aseptic loosening as the major reason for early failure necessitating revision surgery in both total hip and total knee arthroplasty (THA and TKA). Analysis of implant fixation by measuring migration with roentgen stereophotogrammetric analysis (RSA) has shown that the loosening process starts at very early onset after implantation. Implants showing relative high migration during the first post-operative year are prone to failure and subsequent revision later on. However, it is still not crystallized how specific implant characteristics or the surgical procedure affect the implant migration pattern and what degree of initial migration is acceptable without jeopardizing longevity of implant fixation at 10-20 years. In this thesis the migration pattern in relation to longevity of both cemented and cementless stems in THA, the influence of mobile-bearings in TKA on migration and survival, and methods to instantly evaluate implant fixation by inducible displacement have been studied.Atlantic Innovation Fund (Atlantic Canada Opportunities Agency); Biomet; Dutch Arthritis Association; European Information and Communication Technologies Community Seventh Framework ProgrammeLUMC / Geneeskund
The multi-thermal and multi-stranded nature of coronal rain
In this work, we analyse coordinated observations spanning chromospheric, TR
and coronal temperatures at very high resolution which reveal essential
characteristics of thermally unstable plasmas. Coronal rain is found to be a
highly multi-thermal phenomenon with a high degree of co-spatiality in the
multi-wavelength emission. EUV darkening and quasi-periodic intensity
variations are found to be strongly correlated to coronal rain showers.
Progressive cooling of coronal rain is observed, leading to a height dependence
of the emission. A fast-slow two-step catastrophic cooling progression is
found, which may reflect the transition to optically thick plasma states. The
intermittent and clumpy appearance of coronal rain at coronal heights becomes
more continuous and persistent at chromospheric heights just before impact,
mainly due to a funnel effect from the observed expansion of the magnetic
field. Strong density inhomogeneities on spatial scales of 0.2"-0.5" are found,
in which TR to chromospheric temperature transition occurs at the lowest
detectable scales. The shape of the distribution of coronal rain widths is
found to be independent of temperature with peaks close to the resolution limit
of each telescope, ranging from 0.2" to 0.8". However we find a sharp increase
of clump numbers at the coolest wavelengths and especially at higher
resolution, suggesting that the bulk of the rain distribution remains
undetected. Rain clumps appear organised in strands in both chromospheric and
TR temperatures, suggesting an important role of thermal instability in the
shaping of fundamental loop substructure. We further find structure reminiscent
of the MHD thermal mode. Rain core densities are estimated to vary between
2x10^{10} cm^{-3} and 2.5x10^{11} cm^{-3} leading to significant downward mass
fluxes per loop of 1-5x10^{9} g s^{-1}, suggesting a major role in the
chromosphere-corona mass cycle.Comment: Abstract is only short version. See paper for full. Countless pages,
figures (and movies, but not included here). Accepted for publication in the
Astrophysical Journa
Financiering van multifunctionele landbouwbedrijven : zijn er in deze sctor meer knelpunten dan in de reguliere landbouw?
Dit rapport is het resultaat van een verkenning naar de problematiek die agrarische ondernemers met een multifunctionele tak ondervinden met het verkrijgen van financiering in vergelijking met agrarisch ondernemers met alleen (een) agrarische tak(ken) op het landbouwbedrijf. De bevindingen zijn gebaseerd op een enquête onder multifunctionele ondernemers en interviews bij banken. Multifunctionele landbouw is nog een relatief kleine en jonge sector, maar wel een sector met potentie. In tegenstelling tot de reguliere landbouw, is de afzet bij multifunctionele landbouwtakken veelal niet gegarandeerd of is er sprake van een onbekende afzetmarkt. Banken geven aan dat het lastig is om de werkelijke inkomsten uit de nieuwe tak in te schatten. De zekerheden voor de bank van een investering in de multifunctionele tak is beperkter dan bijvoorbeeld investeringen in grond. Voor multifunctionele bedrijven zijn er meer of in ieder geval andere vergunningen en opleidingen nodig, waardoor een ondernemer ‘meer zijn best’ moet doen om zich te presenteren bij een bank. De ondernemer zal vooraf op eigen kosten mogelijk meer zelf moeten (laten) uitzoeken en op papier zetten om de financiering te krijgen Uit dit onderzoek komt niet naar voren dat ondernemers in de multifunctionele landbouw minder kansen hebben om aan een goede financiering te komen,wel dat ze er meer voor moeten doen dan hun collega’s in de reguliere landbouw
Akkerbouw onder hoogspanning : rapport over landbouwkundige gevolgen van 380 kV hoogspanningslijn Noord-Holland
TenneT wil een hoogspanningslijn realiseren van Wateringen naar Beverwijk (TenneT, 2007). In 2011 start de inspraakprocedure. Het voorkeurstracé doorkruist een aantal landbouwgebieden. De Stichting van Bemmelenhoeve heeft Praktijkonderzoek Plant & Omgeving opdracht gegeven om de gevolgen in kaart te brengen voor akkerbouwbedrijven in de buurt van Hoofddor
Unresolved fine-scale structure in solar coronal loop-tops
New and advanced space-based observing facilities continue to lower the resolution limit and detect solar coronal loops in greater detail. We continue to discover even finer substructures within coronal loop cross-sections, in order to understand the nature of the solar corona. Here, we push this lower limit further to search for the finest coronal loop substructures, through taking advantage of the resolving power of the Swedish 1 m Solar Telescope/CRisp Imaging Spectro-Polarimeter (CRISP), together with co-observations from the Solar Dynamics Observatory/Atmospheric Image Assembly (AIA). High-resolution imaging of the chromospheric Hα 656.28 nm spectral line core and wings can, under certain circumstances, allow one to deduce the topology of the local magnetic environment of the solar atmosphere where its observed. Here, we study post-flare coronal loops, which become filled with evaporated chromosphere that rapidly condenses into chromospheric clumps of plasma (detectable in Hα) known as a coronal rain, to investigate their fine-scale structure. We identify, through analysis of three data sets, large-scale catastrophic cooling in coronal loop-tops and the existence of multi-thermal, multi-stranded substructures. Many cool strands even extend fully intact from loop-top to footpoint. We discover that coronal loop fine-scale strands can appear bunched with as many as eight parallel strands within an AIA coronal loop cross-section. The strand number density versus cross-sectional width distribution, as detected by CRISP within AIA-defined coronal loops, most likely peaks at well below 100 km, and currently, 69% of the substructure strands are statistically unresolved in AIA coronal loops.Publisher PDFPeer reviewe
Supporting the changing driver’s task: Exploration of interface designs for supervision and intervention in automated driving
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