Dynamic breakage and fragmentation of brittle single particle of various sizes and strength

2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A THEORETICAL ANALYSIS ON THE MODEL OF POROUS GAS DIFFUSION ELECTRODE

A theoretical discussion on the polarization of porous gas diffusion electrode considering the flooded catalytic agglomerates covered with nonuniform liquid film is presented. Electrochemical reaction, diffusion in gaseous phase, diffusion through liquid film and diffusion in agglomerates are considered simultaneously.The performances of the electrode can be predicted as functions of measurable electrode parameters—characteristic transport currents. Analytical solutions and digital simulations are given and compared with experimental results

Formation of sp³ bonding in nanoindented carbon nanotubes and graphite

Author name used in this publication: C. H. Woo2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

From cellular attractor selection to adaptive signal control for traffic networks

The management of varying traffic flows essentially depends on signal controls at intersections. However, design an optimal control that considers the dynamic nature of a traffic network and coordinates all intersections simultaneously in a centralized manner is computationally challenging. Inspired by the stable gene expressions of Escherichia coli in response to environmental changes, we explore the robustness and adaptability performance of signalized intersections by incorporating a biological mechanism in their control policies, specifically, the evolution of each intersection is induced by the dynamics governing an adaptive attractor selection in cells. We employ a mathematical model to capture such biological attractor selection and derive a generic, adaptive and distributed control algorithm which is capable of dynamically adapting signal operations for the entire dynamical traffic network. We show that the proposed scheme based on attractor selection can not only promote the balance of traffic loads on each link of the network but also allows the global network to accommodate dynamical traffic demands. Our work demonstrates the potential of bio-inspired intelligence emerging from cells and provides a deep understanding of adaptive attractor selection-based control formation that is useful to support the designs of adaptive optimization and control in other domains

Exploring intelligent service migration in vehicular networks

Mobile edge clouds have great potential to address the challenges in vehicular networks by transferring storage and computing functions to the cloud. This brings many advantages of the cloud closer to the mobile user, by installing small cloud infrastructures at the network edge. However, it is still a challenge to efficiently utilize heterogeneous communication and edge computing architectures. In this paper, we investigate the impact of live service migration within a Vehicular Ad-hoc Network environment by making use of the results collected from a real experimental test-bed. A new proactive service migration model which considers both the mobility of the user and the service migration time for different services is introduced. Results collected from a real experimental test-bed of connected vehicles show that there is a need to explore proactive service migration based on the mobility of users. This can result in better resource usage and better Quality of Service for the mobile user. Additionally, a study on the performance of the transport protocol and its impact in the context of live service migration for highly mobile environments is presented with results in terms of latency, bandwidth, and burst and their potential effect on the time it takes to migrate services

Potential applications of nanostructured materials in nuclear waste management.

This report summarizes the results obtained from a Laboratory Directed Research & Development (LDRD) project entitled 'Investigation of Potential Applications of Self-Assembled Nanostructured Materials in Nuclear Waste Management'. The objectives of this project are to (1) provide a mechanistic understanding of the control of nanometer-scale structures on the ion sorption capability of materials and (2) develop appropriate engineering approaches to improving material properties based on such an understanding

MicroRNAs in pulmonary arterial remodeling

Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH

Gravitational Waves from Gravitational Collapse

Gravitational wave emission from the gravitational collapse of massive stars has been studied for more than three decades. Current state of the art numerical investigations of collapse include those that use progenitors with realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non--axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with advanced ground--based and future space--based interferometric observatories.Comment: 68 pages including 13 figures; revised version accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org