4,299 research outputs found
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Impact and Influence Factors of Additive Manufacturing on Product Lifecycle Costs
At first sight the direct costs of Additive Manufacturing (AM) seem too high in comparison to
traditional manufacturing. Considering the whole lifecycle costs of parts changes the point of
view. Due to the modification of the new production process and new supply chains during a
parts lifecycle, producing companies can strongly benefit from AM. Therefore, a costing
model for assessing lifecycle costs with regard to specific applications and branches has been
developed. The costing model represents the advantages of AM monetary. For the evaluation
of this model and the influence factors, different case studies have been performed including
different approaches in part redesign. Deeper research is and will be carried out with respect
to the AM building rates and the comparability of various AM machines, as these facts are
hardly comparable for end users. This paper will present the methodology as well as the
results of the case studies conducted over the whole product lifecycle.Mechanical Engineerin
Recommended from our members
Analyzing Product Lifecycle Costs for a Better Understanding of Cost Drivers in Additive Manufacturing
The costs of additive manufactured parts often seem too high in comparison to those of
traditionally manufactured parts, as the information about major cost drivers, especially for
additive manufactured metal parts, is weak. Therefore, a lifecycle analysis of additive
manufactured parts is needed to understand and rate the cost drivers that act as the largest
contributors to unit costs, and to provide a focus for future cost reduction activities for the
Additive Manufacturing (AM) technology. A better understanding of the cost structure will
help to compare the AM costs with the opportunity costs of the classical manufacturing
technologies and will make it easier to justify the use of AM manufactured parts. This paper
will present work in progress and methodology based on a sample investigated with business
process analysis / simulation and activity based costing. In addition, cost drivers associated
with metal AM process will be rated.Mechanical Engineerin
The merging/AGN connection: A case for 3D spectroscopy
We discuss an ongoing study of the connection between galaxy
merging/interaction and AGN activity, based on integral field spectroscopy. We
focus on the search for AGN ionization in the central regions of mergers,
previously not classified as AGNs. We present here the science case, the
current status of the project, and plans for future observations.Comment: 4 pages, 3 figure, Euro3D Science Workshop, Cambridge, May 2003, AN,
accepte
The VLA-COSMOS Survey. II. Source Catalog of the Large Project
The VLA-COSMOS Large Project is described and its scientific objective is discussed. We present a catalog of ~3600 radio sources found in the 2 deg^2 COSMOS field at 1.4 GHz. The observations in the VLA A and C configuration resulted in a resolution of 1.5" Ă— 1.4" and a mean rms noise of ~10.5 (15) ÎĽJy beam^(-1) in the central 1 (2) deg^2. Eighty radio sources are clearly extended consisting of multiple components, and most of them appear to be double-lobed radio galaxies. The astrometry of the catalog has been thoroughly tested, and the uncertainty in the relative and absolute astrometry are 130 and <55 mas, respectively
Vibrationally Resolved Decay Width of Interatomic Coulombic Decay in HeNe
We investigate the ionization of HeNe from below the He 1s3p excitation to
the He ionization threshold. We observe HeNe ions with an enhancement by
more than a factor of 60 when the He side couples resonantly to the radiation
field. These ions are an experimental proof of a two-center resonant
photoionization mechanism predicted by Najjari et al. [Phys. Rev. Lett. 105,
153002 (2010)]. Furthermore, our data provide electronic and vibrational state
resolved decay widths of interatomic Coulombic decay (ICD) in HeNe dimers. We
find that the ICD lifetime strongly increases with increasing vibrational
state.Comment: 7 pages, 5 figure
Interatomic-Coulombic-decay-induced recapture of photoelectrons in helium dimers
We investigate the onset of photoionization shakeup induced interatomic
Coulombic decay (ICD) in He2 at the He+*(n = 2) threshold by detecting two He+
ions in coincidence. We find this threshold to be shifted towards higher
energies compared to the same threshold in the monomer. The shifted onset of
ion pairs created by ICD is attributed to a recapture of the threshold
photoelectron after the emission of the faster ICD electron.Comment: 5 Pages, 2 Figure
A measurement of the evolution of Interatomic Coulombic Decay in the time domain
During the last 15 years a novel decay mechanism of excited atoms has been
discovered and investigated. This so called ''Interatomic Coulombic Decay''
(ICD) involves the chemical environment of the electronically excited atom: the
excitation energy is transferred (in many cases over long distances) to a
neighbor of the initially excited particle usually ionizing that neighbor. It
turned out that ICD is a very common decay route in nature as it occurs across
van-der-Waals and hydrogen bonds. The time evolution of ICD is predicted to be
highly complex, as its efficiency strongly depends on the distance of the atoms
involved and this distance typically changes during the decay. Here we present
the first direct measurement of the temporal evolution of ICD using a novel
experimental approach.Comment: 6 pages, 4 figures, submitted to PR
Systematic study of carrier correlations in the electron-hole recombination dynamics of quantum dots
The ground state carrier dynamics in self-assembled (In,Ga)As/GaAs quantum
dots has been studied using time-resolved photoluminescence and transmission.
By varying the dot design with respect to confinement and doping, the dynamics
is shown to follow in general a non-exponential decay. Only for specific
conditions in regard to optical excitation and carrier population, for example,
the decay can be well described by a mono-exponential form. For resonant
excitation of the ground state transition a strong shortening of the
luminescence decay time is observed as compared to the non-resonant case. The
results are consistent with a microscopic theory that accounts for deviations
from a simple two-level picture.Comment: 8 pages, 7 figure
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