The optical anisotropy of Au protected Fe layers grown on a vicinal W(110) surface has been investigated using reflectance anisotropy spectroscopy (RAS). Iron nanostripes formed at submonolayer coverage, as well as Fe layers up to 3 ML coverage, were protected by 12 and 16 nm gold caps and measured ex situ under ambient conditions. The RAS is dominated by structures originating in the interfaci...

One commonly employed method to calculate whether a wireless sensor network can adequately sense the entirety of a region of interest is to define the area that a sensor can monitor and ensure that the union of all these areas leaves no part of the region uncovered. This paper shows the results of a series of experiments in simulation designed to show how various degrees of deviation from inten...

We present an experimental and theoretical study to provide further insight into the mechanism of CO chemisorption on 2 carbonaceous surfaces. The differential heat of CO adsorption at low and high coverages was determined in the temperature 2 range 553–593 K. We found that the heat profile has two distinct energetic zones that suggest two different adsorption processes. In the low-coverage reg...

OBJECTIVE To assess the progress made towards meeting the goals of the African Regional Strategic Plan of the Expanded Programme on Immunization between 2001 and 2005. METHODS We reviewed data from national infant immunization programmes in the 46 countries of WHOs African Region, reviewed the literature and analysed existing data sources. We carried out face-to-face and telephone interviews ...

Considered is a class of pursuit-evasion games, in which an evader tries to avoid detection. Such games can be formulated as the search for sections to the complement of a coverage region in a Euclidean space over a timeline. Prior results give homological criteria for evasion in the general case that are not necessary and sufficient. This paper provides a necessary and sufficient positive coho...

Wireless sensor networks are emerging as a new computational platform consisting of small, low-power and inexpensive nodes used in a broad set of application areas including environmental monitoring, habitat monitoring and disaster recovery. Typically sensor nodes are deployed over a geographical area for the purpose of detecting, tracking and monitoring events of interest. Since sensor nodes a...

In wireless sensor networks, sensors are often batterypowered and cannot be recharged. Even the simple act of sensing its environment can consume significant amounts of these devices’ energy. To reduce the likelihood that an insufficient number of sensors are deployed within a region, sensors will often be deployed at a greater density than what is expected to be necessary. The sensing devices ...

The multi-robot coverage path-planning problem involves finding collision-free paths for a set of robots so that they can completely cover the surface of an environment. This problem is non-trivial as the geometry and location of obstacles in the environment is usually not known a priori by the robots, and they have to adapt their coverage path as they discover obstacles while moving in the env...

the global investigation of disasters in recent years shows that their number has increased annually and the number of affected people and costs of disasters are increasing

The World Health Organization (WHO) African Region has approximately 100 million people with chronic hepatitis B virus (HBV) infection. This review describes the status of hepatitis B control in the Region. We present hepatitis B vaccine (HepB) coverage data and from available data in the published literature, the impact of HepB vaccination on hepatitis B surface antigen (HBsAg) prevalence, a m...