6,605 research outputs found
An Ontology based System for Cloud Infrastructure Services Discovery
The Cloud infrastructure services landscape advances steadily leaving users
in the agony of choice. As a result, Cloud service identification and discovery
remains a hard problem due to different service descriptions, non standardised
naming conventions and heterogeneous types and features of Cloud services. In
this paper, we present an OWL based ontology, the Cloud Computing Ontology
(CoCoOn) that defines functional and non functional concepts, attributes and
relations of infrastructure services. We also present a system...Comment: Accepted as an invited paper by Collaboratecom 201
Dust trapping in inviscid vortex pairs
The motion of tiny heavy particles transported in a co-rotating vortex pair,
with or without particle inertia and sedimentation, is investigated. The
dynamics of non-inertial sedimenting particles is shown to be chaotic, under
the combined effect of gravity and of the circular displacement of the
vortices. This phenomenon is very sensitive to particle inertia, if any. By
using nearly hamiltonian dynamical system theory for the particle motion
equation written in the rotating reference frame, one can show that small
inertia terms of the particle motion equation strongly modify the Melnikov
function of the homoclinic trajectories and heteroclinic cycles of the
unperturbed system, as soon as the particle response time is of the order of
the settling time (Froude number of order unity). The critical Froude number
above which chaotic motion vanishes and a regular centrifugation takes place is
obtained from this Melnikov analysis and compared to numerical simulations.
Particles with a finite inertia, and in the absence of gravity, are not
necessarily centrifugated away from the vortex system. Indeed, these particles
can have various equilibrium positions in the rotating reference frame, like
the Lagrange points of celestial mechanics, according to whether their Stokes
number is smaller or larger than some critical value. An analytical stability
analysis reveals that two of these points are stable attracting points, so that
permanent trapping can occur for inertial particles injected in an isolated
co-rotating vortex pair. Particle trapping is observed to persist when
viscosity, and therefore vortex coalescence, is taken into account. Numerical
experiments at large but finite Reynolds number show that particles can indeed
be trapped temporarily during vortex roll-up, and are eventually centrifugated
away once vortex coalescence occurs.Comment: 7 figure
Adaptive Engine Technologies for Aviation CO2 Emissions Reduction
Adaptive turbine engine technologies are assessed for their potential to reduce carbon dioxide emissions from commercial air transports.Technologies including inlet, fan, and compressor flow control, compressor stall control, blade clearance control, combustion control, active bearings and enabling technologies such as active materials and wireless sensors are discussed. The method of systems assessment is described, including strengths and weaknesses of the approach. Performance benefit estimates are presented for each technology, with a summary of potential emissions reduction possible from the development of new, adaptively controlled engine components
Got milk? Breastfeeding and milk analysis of a mother on chronic hemodialysis
Purpose: Women on dialysis rarely become pregnant. However, the overall rate of successful pregnancies is increasing in this patient population and breastfeeding becomes an option for mothers on dialysis. In this study we performed a systematic breast milk composition analysis of a mother on chronic hemodialysis (HD).
Methods: Specimens of breast milk and blood were collected in regular intervals before and after HD from a 39-year old woman starting on day 10 postpartum. Samples were analyzed for electrolytes, retention solutes, nutrients and other laboratory measurements. Breast milk samples from low-risk mothers matched for postpartum age were used as controls.
Results: Significantly higher levels of creatinine and urea were found in pre-HD breast milk when compared to post-HD. A similar post-dialytic decrease was only found for uric acid but not for any other investigated parameter. Conversely, sodium and chloride were significantly increased in post-HD samples. Compared to controls creatinine and urea were significantly higher in pre-HD samples while the difference remained only significant for post-HD creatinine. Phosphate was significantly lower in pre- and post-HD breast milk when compared to controls, whereas calcium showed no significant differences. In terms of nutrient components glucose levels showed a strong trend for a decrease, whereas protein, triglycerides and cholesterol did not differ. Similarly, no significant differences were found in iron, potassium and magnesium content.
Conclusion: To the best of our knowledge this is the first report on a breastfeeding mother on chronic dialysis. Although we found differences in creatinine, urea, sodium, chloride and phosphate, our general analysis showed high similarity of our patient’s breast milk to samples from low-risk control mothers. Significant variations in breast milk composition between pre- and post-HD samples suggest that breastfeeding might be preferably performed after dialysis treatment. In summary, our findings indicate that breastfeeding can be considered a viable option for newborns of mothers on dialysis
Got milk? Breastfeeding and milk analysis of a mother on chronic hemodialysis
Purpose: Women on dialysis rarely become pregnant. However, the overall rate of successful pregnancies is increasing in this patient population and breastfeeding becomes an option for mothers on dialysis. In this study we performed a systematic breast milk composition analysis of a mother on chronic hemodialysis (HD).
Methods: Specimens of breast milk and blood were collected in regular intervals before and after HD from a 39-year old woman starting on day 10 postpartum. Samples were analyzed for electrolytes, retention solutes, nutrients and other laboratory measurements. Breast milk samples from low-risk mothers matched for postpartum age were used as controls.
Results: Significantly higher levels of creatinine and urea were found in pre-HD breast milk when compared to post-HD. A similar post-dialytic decrease was only found for uric acid but not for any other investigated parameter. Conversely, sodium and chloride were significantly increased in post-HD samples. Compared to controls creatinine and urea were significantly higher in pre-HD samples while the difference remained only significant for post-HD creatinine. Phosphate was significantly lower in pre- and post-HD breast milk when compared to controls, whereas calcium showed no significant differences. In terms of nutrient components glucose levels showed a strong trend for a decrease, whereas protein, triglycerides and cholesterol did not differ. Similarly, no significant differences were found in iron, potassium and magnesium content.
Conclusion: To the best of our knowledge this is the first report on a breastfeeding mother on chronic dialysis. Although we found differences in creatinine, urea, sodium, chloride and phosphate, our general analysis showed high similarity of our patient’s breast milk to samples from low-risk control mothers. Significant variations in breast milk composition between pre- and post-HD samples suggest that breastfeeding might be preferably performed after dialysis treatment. In summary, our findings indicate that breastfeeding can be considered a viable option for newborns of mothers on dialysis
Entwicklungsperspektiven der ökologischen Landwirtschaft in Deutschland
Hohe Umweltbelastungen und eine wachsende Weltbevölkerung stellen die Landwirtschaft vor große Herausforderungen. Die ökologische Landwirtschaft gilt dabei als besonders umweltfreundlich. Die Studie zeigt: Ökolandbau ist gut, aber nicht optimal. Einige seiner Prinzipien erschweren es die Ökoeffizienz (Umweltwirkung pro Produkteinheit) zu verbessern. Ein Ökolandbau 4.0, der offener gegenüber Neuerungen wäre, würde hier Abhilfe schaffen. Um die Ökoeffizienz der konventionellen Landwirtschaft zu steigern, wird die Etablierung eines neuen Standards - der ökologisch optimierten, integrierten Produktion (IP+) - vorgeschlagen. Die Studie zeigt somit Entwicklungsperspektiven für den Ökolandbau und die konventionelle Landwirtschaft gleichermaßen auf
An N+3 Technology Level Reference Propulsion System
An N+3 technology level engine, suitable as a propulsion system for an advanced single-aisle transport, was developed as a reference cycle for use in technology assessment and decision-making efforts. This reference engine serves three main purposes: it provides thermodynamic quantities at each major engine station, it provides overall propulsion system performance data for vehicle designers to use in their analyses, and it can be used for comparison against other proposed N+3 technology-level propulsion systems on an equal basis. This reference cycle is meant to represent the expected capability of gas turbine engines in the N+3 timeframe given reasonable extrapolations of technology improvements and the ability to take full advantage of those improvements
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