Wireless Sensor Networks (WSNs) have existed for many years and had assimilated many interesting innovations. Advances in electronics, radio transceivers, processes of IC manufacturing and development of algorithms for operation of such networks now enable creating energy-efficient devices that provide practical levels of performance and a sufficient number of features. Environmental monitoring is one of the areas in which WSNs can be successfully used. At the same time this is a field where devices must either bring their own power reservoir, such as a battery, or scavenge energy locally from some natural phenomena. Improving the efficiency of energy harvesting methods reduces complexity of WSN structures. This survey is based on practical examples from the real world and provides an overview of state-of-the-art methods and techniques that are used to create energyefficient WSNs with energy harvesting.

This paper aims to present new trends in energy-harvesting solutions pertaining to wearable sensors and powering Body Area Network nodes. To begin, we will present the capability of human beings to generate energy. We then examine solutions for converting kinetic and thermal energy from the human body. As part of our review of kinetic converters, we survey the structures and performance of electromagnetic, piezoelectric, and triboelectric systems. Afterward, we discuss thermal energy converters that utilize the heat generated by humans. In the final section, we present systems for converting energy from the electromagnetic waves surrounding a person. A number of these systems are suitable for use as wearables, such as RF harvesters and micro photovoltaic cells.

We present the mobile observation point (MOP) and a system for monitoring hydrocarbons. This paper describes the technical problems in the development of the monitoring system and the MOP. We pay particular attention to procedures that predict measurement results and issue alerts about oil spills in water. This paper gives a comparison between the transmission performance of a binary stream and the Jabber protocol. Finally, we discuss the advantages and disadvantages of the proposed solutions.

In this paper, some issues of building a reliable, distributed measurement system for monitoring of water quality in reservoir Lake Dobczyckie are presented. The system is based on a measurement station that has the shape of a floating buoy which is supposed to be at anchor on the reservoir. Wireless data transmission problems that were encountered during the development of the buoy, modeling a radio link, and measurements of actual signal strength on the reservoir are discussed. A mathematical approach to procedures of early situation assessment was conducted, and specialized procedures were designed for measurement stations of the system. It is also discussed how such computations can improve a qualitative assessment of system performance in terms of real-time messaging

The simplified field-system functionality testing software (FSFTS) was presented. That software was successfully used for verification of the final system functionality and the quality evaluation of its components. Then, two solutions for the server/client software for the distributed measurement system, implementing the Web as a main transmission medium, were described. The essential parts of the final system solutions are the server and the clients. The server collects remote data and makes them accessible for clients. These two solutions of the server/client system are based on a Windows operating system. The first solution implements Microsoft's .NET environment. The second one uses WAMP (Windows and free and open source software: Apache, MySQL, and PHP). The main difference between the first two solutions is how the client page is generated. The .NET case is only on the server side, and the WAMP case is on both server and client sides. Both systems produce a map/plot/ table showing the system data to the user through web browsers.

For pt. 1 see ibid., vol.11, no.2, p.50-56, (2008). This paper provides an explanation of a distributed measurement system based on proprietary software. It describes applications based mainly on free and open source software (FOSS). It is an interesting alternative to proprietary solutions as it offers greater flexibility in software development, better protection of customers' rights, and guaranteed open access to data. FOSS is based on the IEEE standards 1003, also known as POSIX or ISO/IEC 9945. In this paper, it is shown that the same objectives met with proprietary solutions can be achieved with FOSS, if not even better than with proprietary software.