63 research outputs found
Using Collaborative Immersive Environments and Building Information Modeling Technology for Holistic Planning of Production Lines
Large and complex building projects need many different experts from different engineering disciplines for different matters. But these experts each use their own IT tools that produce a lot of heterogeneous data. This leads to a strong fragmentation of competencies, what causes problems for interdisciplinary collaboration, because the data might be inconsistent, redundant or there are no interfaces to combine the data. These problems in collaboration increase the risk of planning mistakes that might significantly impair the overall project success. So only one database should be used for all engineering tasks to improve the transdisciplinary collaboration. The Building Information Modelling (BIM) working methodology enables the digital collaboration of virtual production planning and architecture tasks for developing a building. By means of lean optimization in combination with early integration of future-oriented production facilities, process-relevant production data can be included in the planning phase before construction begins. This article presents a real time immersive 3D virtualization system using the digital twin of complex buildings with a modern production line as the single source of truth and creates a consistent integrated data model, that enables transdisciplinary collaboration of all involved engineering disciplines. In this way, a continuous comparison can be made between the real construction project and its digital twin in an interactive, intuitive and collaborative manner. The same model is also used by production planners to optimize the material flow and in general the value chain of a production line through a holistic planning, which brings many benefits for all stakeholders
X-ray Emission from the FU Orionis Star V1735 Cygni
The variable star V1735 Cyg (= Elias 1-12) lies in the IC 5146 dark cloud and
is a member of the class of FU Orionis objects whose dramatic optical
brightenings are thought to be linked to episodic accretion. We report the
first X-ray detections of V1735 Cyg and a deeply-embedded class I protostar
lying 24 arcsecs to its northeast. X-ray spectra obtained with EPIC on
XMM-Newton reveal very high-temperature plasma (kT > 5 keV) in both objects,
but no large flares. Such hard X-ray emission is not anticipated from accretion
shocks and is a signature of magnetic processes. We place these new results
into the context of what is presently known about the X-ray properties of FU
Orionis stars and other accreting young stellar objects.Comment: 25 pages, 6 figure
The Far-Ultraviolet "Continuum" in Protoplanetary Disk Systems I: Electron-Impact H2 and Accretion Shocks
We present deep spectroscopic observations of the classical T Tauri stars DF
Tau and V4046 Sgr in order to better characterize two important sources of
far-ultraviolet continuum emission in protoplanetary disks. These new Hubble
Space Telescope-Cosmic Origins Spectrograph observations reveal a combination
of line and continuum emission from collisionally excited H2 and emission from
accretion shocks. H2 is the dominant emission in the 1400-1650 A band spectrum
of V4046 Sgr, while an accretion continuum contributes strongly across the
far-ultraviolet spectrum of DF Tau. We compare the spectrum of V4046 Sgr to
models of electron-impact induced H2 emission to constrain the physical
properties of the emitting region, after making corrections for attenuation
within the disk. We find reasonable agreement with the broad spectral
characteristics of the H2 model, implying N(H2) ~ 10^{18} cm^{-2}, T(H2) =
3000^{+1000}_{-500} K, and a characteristic electron energy in the range of ~
50 - 100 eV. We propose that self-absorption and hydrocarbons provide the
dominant attenuation for H2 line photons originating within the disk. For both
DF Tau and V4046 Sgr, we find that a linear fit to the far-UV data can
reproduce near-UV/optical accretion spectra. We discuss outstanding issues
concerning how these processes operate in protostellar/protoplanetary disks,
including the effective temperature and absolute strength of the radiation
field in low-mass protoplanetary environments. We find that the 912-2000A
continuum in low-mass systems has an effective temperature of ~10^{4} K with
fluxes 10^{5-7} times the interstellar level at 1 AU.Comment: 14 pages, 8 figures, 3 tables. ApJ, accepte
Evaluation of a clinical decision support tool for osteoporosis disease management: protocol for an interrupted time series design
<p>Abstract</p> <p>Background</p> <p>Osteoporosis affects over 200 million people worldwide at a high cost to healthcare systems. Although guidelines on assessing and managing osteoporosis are available, many patients are not receiving appropriate diagnostic testing or treatment. Findings from a systematic review of osteoporosis interventions, a series of mixed-methods studies, and advice from experts in osteoporosis and human-factors engineering were used collectively to develop a multicomponent tool (targeted to family physicians and patients at risk for osteoporosis) that may support clinical decision making in osteoporosis disease management at the point of care.</p> <p>Methods</p> <p>A three-phased approach will be used to evaluate the osteoporosis tool. In phase 1, the tool will be implemented in three family practices. It will involve ensuring optimal functioning of the tool while minimizing disruption to usual practice. In phase 2, the tool will be pilot tested in a quasi-experimental interrupted time series (ITS) design to determine if it can improve osteoporosis disease management at the point of care. Phase 3 will involve conducting a qualitative postintervention follow-up study to better understand participants' experiences and perceived utility of the tool and readiness to adopt the tool at the point of care.</p> <p>Discussion</p> <p>The osteoporosis tool has the potential to make several contributions to the development and evaluation of complex, chronic disease interventions, such as the inclusion of an implementation strategy prior to conducting an evaluation study. Anticipated benefits of the tool may be to increase awareness for patients about osteoporosis and its associated risks and provide an opportunity to discuss a management plan with their physician, which may all facilitate patient self-management.</p
PTF10nvg: An Outbursting Class I Protostar in the Pelican/North American Nebula
During a synoptic survey of the North American Nebula region, the Palomar
Transient Factory (PTF) detected an optical outburst (dubbed PTF10nvg)
associated with the previously unstudied flat or rising spectrum infrared
source IRAS 20496+4354. The PTF R-band light curve reveals that PTF10nvg
brightened by more than 5 mag during the current outburst, rising to a peak
magnitude of R~13.5 in 2010 Sep. Follow-up observations indicate PTF10nvg has
undergone a similar ~5 mag brightening in the K band, and possesses a rich
emission-line spectrum, including numerous lines commonly assumed to trace mass
accretion and outflows. Many of these lines are blueshifted by ~175 km/s from
the North American Nebula's rest velocity, suggesting that PTF10nvg is driving
an outflow. Optical spectra of PTF10nvg show several TiO/VO bandheads fully in
emission, indicating the presence of an unusual amount of dense (> 10^10
cm^-3), warm (1500-4000 K) circumstellar material. Near-infrared spectra of
PTF10nvg appear quite similar to a spectrum of McNeil's Nebula/V1647 Ori, a
young star which has undergone several brightenings in recent decades, and
06297+1021W, a Class I protostar with a similarly rich near--infrared emission
line spectrum. While further monitoring is required to fully understand this
event, we conclude that the brightening of PTF10nvg is indicative of enhanced
accretion and outflow in this Class-I-type protostellar object, similar to the
behavior of V1647 Ori in 2004-2005.Comment: Accepted to the Astronomical Journal; 21 pages, 11 figures, 6 tables
in emulateapj format; v2 fixes typo in abstract; v3 updates status to
accepted, adjusts affiliations, adds acknowledgmen
Carbon release from submarine seeps at the Costa Rica fore arc: implications for the volatile cycle at the Central America convergent margin
We report total dissolved inorganic carbon (DIC) abundances and isotope ratios, as well as helium isotope ratios (3He/4He), of cold seep fluids sampled at the Costa Rica fore arc in order to evaluate the extent of carbon loss from the submarine segment of the Central America convergent margin. Seep fluids were collected over a 12 month period at Mound 11, Mound 12, and Jaco Scar using copper tubing attached to submarine flux meters operating in continuous pumping mode. The fluids show minimum 3He/4He ratios of 1.3 RA (where RA is air 3He/4He), consistent with a small but discernable contribution of mantle-derived helium. At Mound 11, δ13C∑CO2 values between −23.9‰ and −11.6‰ indicate that DIC is predominantly derived from deep methanogenesis and is carried to the surface by fluids derived from sediments of the subducting slab. In contrast, at Mound 12, most of the ascending dissolved methane is oxidized due to lower flow rates, giving extremely low δ13C∑CO2 values ranging from −68.2‰ to −60.3‰. We estimate that the carbon flux (CO2 plus methane) through submarine fluid venting at the outer fore arc is 8.0 × 105 g C km−1 yr−1, which is virtually negligible compared to the total sedimentary carbon input to the margin and the output at the volcanic front. Unless there is a significant but hitherto unidentified carbon flux at the inner fore arc, the implication is that most of the carbon being subducted in Costa Rica must be transferred to the (deeper) mantle, i.e., beyond the depth of arc magma generation
An Open Resource for Non-human Primate Imaging.
Non-human primate neuroimaging is a rapidly growing area of research that promises to transform and scale translational and cross-species comparative neuroscience. Unfortunately, the technological and methodological advances of the past two decades have outpaced the accrual of data, which is particularly challenging given the relatively few centers that have the necessary facilities and capabilities. The PRIMatE Data Exchange (PRIME-DE) addresses this challenge by aggregating independently acquired non-human primate magnetic resonance imaging (MRI) datasets and openly sharing them via the International Neuroimaging Data-sharing Initiative (INDI). Here, we present the rationale, design, and procedures for the PRIME-DE consortium, as well as the initial release, consisting of 25 independent data collections aggregated across 22 sites (total = 217 non-human primates). We also outline the unique pitfalls and challenges that should be considered in the analysis of non-human primate MRI datasets, including providing automated quality assessment of the contributed datasets
- …