2,013 research outputs found
Asymptotically AdS brane black holes
We study the possibility of having a static, asymptotically AdS black hole
localized on a braneworld with matter fields, within the framework of the
Randall and Sundrum scenario. We attempt to look for such a brane black hole
configuration by slicing a given bulk spacetime and taking Z_2 symmetry about
the slices. We find that such configurations are possible, and as an explicit
example, we provide a family of asymptotically AdS brane black hole solutions
for which both the bulk and brane metrics are regular on and outside the black
hole horizon and brane matter fields are realistic in the sense that the
dominant energy condition is satisfied. We also find that our braneworld models
exhibit signature change inside the black hole horizon.Comment: 21 pages, 6 figures, RevTex; v2: clarifications added, figures
updated, eq.31 corrected, comment on small four dimensional cosmological
constant limit added, character size increased, results unchanged. v3:
reference added, version accepted in Phys. Rev. D (2006
A New Class of Four-Dimensional N=1 Supergravity with Non-minimal Derivative Couplings
In the N=1 four-dimensional new-minimal supergravity framework, we
supersymmetrise the coupling of the scalar kinetic term to the Einstein tensor.
This coupling, although introduces a non-minimal derivative interaction of
curvature to matter, it does not introduce harmful higher-derivatives. For this
construction, we employ off-shell chiral and real linear multiplets. Physical
scalars are accommodated in the chiral multiplet whereas curvature resides in a
linear one.Comment: 18 pages, version published at JHE
Cost Sensitivity Analysis for Laser Powder Bed Fusion
Laser Powder Bed Fusion is the most widespread additive manufacturing process for metals. In literature, there are several analytical models for estimating the manufacturing cost. However, few papers present sensitivity analyses for evaluating the most relevant product and process parameters on the production cost. This paper presents a cost model elaborated from previous studies used in a sensitivity analysis. The most relevant process parameters observed in the sensitivity analysis are the 3D printer load factor, layer thickness, raw material price and laser speed
Résultats de traitements nématicides contre la chlorose et le rabougrissement de l'arachide en Haute-Volta
Direct fabrication through electron beam melting technology of custom cranial implants designed in a phantom based haptic
Repairing critical human skull injuries requires the production and use of customized cranial implants and involves the integration of computer aided design and manufacturing (CAD and CAM). The main causes for large cranial defects are trauma, cranial tumors, infected craniotomy bone flaps and external neurosurgical decompression. The success of reconstructive cranial surgery depends upon: the preoperative evaluation of the defect, the design and manufacturing of the implant, and the skill of the operating surgeon. Cranial implant design is usually carried out manually using CAD although this process is very time-consuming and the quality of the end product depends wholly upon the skill of the operator. This paper presents an alternative automated method for the design of custom-made cranial plates in a PHANToM \uae-based haptic environment, and their direct fabrication in biocompatible metal using electron beam melting (EBM) technology
LTV stochastic systems stabilization with large and variable input delay
In this paper we propose a solution to the state-feedback and output-feedback stabilization problem for linear time-varying stochastic systems affected by arbitrarily large and variable input delay. It is proved that under the proposed controller the underlying stochastic process is exponentially centered and mean square bounded. The solution is given through a set of delay differential equations with cardinality proportional to the delay bound. The predictor is based on the semigroup generated by the closed-loop system in absence of delay, and its computation is described by a numerically reliable and robust method. In the deterministic case this method generates the same optimal trajectories as in the delay-less case
Elaboração de biscoitos tipo salgado, com alto teor de fibra alimentar, utilizando farinha de berinjela (Solanum melongena, L.).
A Framework to Collect and Reuse Engineering Knowledge in the Context of Design for Additive Manufacturing
Design for AM (DfAM) requires the definition of Design Actions (DAs) to optimize AM manufacturing processes. However, AM understanding is still very blurred. Often designers are challenged by selecting the right design parameters. A method to list and collect DfAM DAs is currently missing. The paper aims at providing a framework to collect DfAM DAs according to a developed ontology to create databases (DBs). DBs were tested with two real case studies and geometric features to improve identified. Future developments aim at widening the database to provide all-around support for AM processes
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