Robotic Wireless Sensor Networks

In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

Molecular mechanisms of vaspin action: from adipose tissue to skin and bone, from blood vessels to the brain

Visceral adipose tissue derived serine protease inhibitor (vaspin) or SERPINA12 according to the serpin nomenclature was identified together with other genes and gene products that  were specifically expressed or overexpressed in the intra abdominal or visceral adipose tissue  (AT) of the Otsuka Long-Evans Tokushima fatty rat. These rats spontaneously develop visceral  obesity, insulin resistance, hyperinsulinemia and ‐glycemia, as well as hypertension and thus represent a well suited animal model of obesity and related metabolic disorders such as type  2 diabetes.  The follow-up study reporting the cloning, expression and functional characterization of  vaspin suggested the great and promising potential of this molecule to counteract obesity induced insulin resistance and inflammation and has since initiated over 300 publications, clinical and experimental, that have contributed to uncover the multifaceted functions and molecular mechanisms of vaspin action not only in the adipose, but in many different cells, tissues and organs. This review will give an update on mechanistic and structural aspects of vaspin with a focus on its serpin function, the physiology and regulation of vaspin expression, and will summarize the latest on vaspin function in various tissues such as the different adipose tissue depots as well as the vasculature, skin, bone and the brain

A density functional study of small Li-B and Li-B-H clusters

WOS: 000267562100013In this work we present the results of a detailed theoretical research for the small LinBm clusters and their hydrogen storage properties by means of density functional theory. All calculations were performed by using Gaussian03 program. For the optimization of the clusters 6-311++G(d,p) basis set was employed. We have chosen global minimum of B-6 cluster as the starting point and replaced the boron atoms one at a time, in a stepwise manner, with Li atoms. For these new structures we have searched for the stable configurations, and calculated their energies, HOMO-LUMO energy gaps, Raman and infrared data, average boron, and lithium charge distribution, and vibrational frequencies. Our results show that as the number of Li atoms increases, stability of the clusters decreases and they become more reactive. In addition to that, there are significant charge transfers from boron atoms to lithium atoms on average. The hydrogen storage capabilities of the most stable isomers of LinBm and B-6 clusters have also been investigated by the same methods, and the results are compared. The Li3B3 has the highest hydrogen storage capacity among the clusters investigated in this study. Furthermore, formation of hydrogen molecules is observed in the vicinity of the clusters, some of which are attached to the Li atoms. In addition, as the number of hydrogen atoms increases, the boron atoms are separated from the other boron atoms, and they form satellite BHx (x = 3,4) clusters around the center. These are attached to the system by a bridging bond of a hydrogen or a Li atom. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.KIRIKKALE UNIVERSITYKirikkale University [2008/21]; CANKAYA UNIVERSITYCankaya University; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [10ST084]We would like to thank KIRIKKALE UNIVERSITY and CANKAYA UNIVERSITY for the support they provided. This work is supported through the Kirikkale University BAP Project number 2008/21, and TUBITAK project number 10ST084, 2005

Differences in melting behaviours of disordered and symmetric clusters: Au(N)(N=54-56)

WOS: 000239703300005We have investigated the melting behaviours of disordered and symmetric gold clusters (Au(N), N = 54 - 56) by means of molecular dynamics simulations. We have found that there is no single isolated lowest energy structure for this size of Au clusters. Instead there are many nearly degenerate disordered low lying structures. The melting behaviours of these disordered structures showed that the melting occurs as a gradual process in which initially, behaviours of the surface and the inner atoms are quite different from each other, and they do not mix until the beginning of the melting. On the other hand, the symmetric forms of the Au(N) ( N = 54 - 56) present different melting behaviours from those of the corresponding disordered structures. Their melting occurs suddenly, i.e. over a very short temperature interval. During the heating of these symmetric forms no phase changes occur until the melting temperature at which melting occurs as a collective motion of all the atoms in the cluster. On the other hand, the phase changes in the disordered structures take place as a result of both collective motions of all the atoms in the cluster, and as local displacements of the atoms

Molecular dynamics simulation of melting behaviour of small gold clusters: Au-N (N=12-14)

ATIS, Murat/0000-0003-4429-6897WOS: 000243928000018We have investigated the melting behaviour of AuN (N = 12 - 14) clusters by means of molecular dynamics simulation on the basis of the Voter - Chen version of the embedded-atom method. The melting behaviour of the clusters is described in terms of short-time average temperatures and atomic coordination numbers of the clusters. Results have shown that during the melting process, the phase changes occur as a collective and simultaneous motion of all the atoms in a very short-time interval. Furthermore the Au-14 cluster presents a two-stage melting behaviour which is different from those of the Au-12 and Au-13 clusters. The isomer sampling probabilities are obtained from the thermal quenching of the molten clusters, and their energy-spectrum widths are investigated. The results of the isomer forming probabilities showed that the global minimum structures of these clusters are not always the most probable ones to be formed in the experiments

Molecular Dynamics Simulation of the Melting Behaviours of 12-, 13-, 14-Atom Icosahedral Platinum Clusters

Using molecular dynamics simulation technique, we have studied the melting behaviours of free, icosahedral PtN clusters in the size range of N=12-14. Voter and Chen version of an embedded-atom model, derived by fitting to experimental data of both diatomic molecule and bulk platinum simultaneously, has been employed in the study. We present an atom-resolved analysis method that includes physical quantities such as the root-mean-square bond-length fluctuation and coordination number for individual atoms as functions of temperature. The results show that while 13-atom icosahedron and 12-atom cluster with a vacancy on the icosahedral surface exhibit one-stage melting, 14-atom cluster with an adatom on the icosahedral surface undergoes two-stage melting, as the temperature increases.Comment: 5 pages, 3 figures, submitted to ECOSS 2