Recent Patents on Engineering - Volume 5, Issue 1, 2011

This paper is a tutorial review for coherent optical communication with emphasis on digital coherent receivers because digital coherent optical receivers are promising solution for next generation optical communication systems. In this paper, principles of coherent communication has been reviewed along with its advantages and prospective modulation formats to achieve 111 Gbps. Digital coherent receivers and their signal processing modules have been reviewed in the light of recent publications and patents. In the end, realization challenges have been addressed from circuit and signal processing point of view.

This review will cover the application of supercritical of fluid extraction (SFE) for obtaining volatile oils (VOs) from aromatic, spice and medicinal plants. A brief discussion of advantages and disadvantages of SFE for obtaining these very complex mixtures of substances will be presented. The chemical profile of volatiles oils obtained by SFE will be compared with that obtained by the conventional process, that is, steam distillation. Applications of SFE to obtain clove and chamomile volatiles oils based on the LASEFI's experience will also be considered. Finally, we will successively detail the patent evolution over time involving extraction of VOs by SFE that have been claimed.

The need for countries to become less dependent on fossil fuels has been determinant in recent years due to increasing energy and comfort concerns in modern building design. Therefore, the maximization of the use of renewable energies, like the sun, and the use of natural energy flows become strategies to explore. There are already passive building systems that show interesting performances. Different studies have proved that the above-mentioned systems can lead to important energy savings. However, these systems have their limitations and new innovative building solutions are needed, mainly in the field of passive solar energy collection and natural ventilation strategies. Furthermore, building envelopes face nowadays a new paradigm in which buildings need to be more reactive and adaptive to external climate changes and indoor thermal comfort demands. Hence, this paper makes a review of the most recent patents on building solar air systems that make use of solar energy to induce the buoyancy effect for heating, cooling and ventilating. The patents presented demonstrate the increasing tendency in the development of building passive solutions that can satisfy, in just one system, more than one role: heating, cooling and ventilation.

Though passive gravity-force compensation or weight balancing technology has existed for centuries, novel system designs and new applications have been emerging in the past two decades. This survey paper reviews the recent patents and technical publications related to these new developments and applications. The paper first gives an overview of widely used passive gravity-force compensation techniques. It then presents the applications of these techniques in different areas with focus on the recent patents and publications. Finally, the likely trends of future development in this particular area are discussed.

This paper introduces the patented technology of “soft-dam coastal reservoir”. Compared to the conventional technology of solid-dam coastal reservoir or long-distance water diversion, the patented technology is easier to implement with lower cost. As an example, the paper discusses the application of this technology in Murray-Darling River, Australia and Yellow River, China for water resources management. Both catchments are currently facing the similar problems of water shortage, degradation of water quality, and the threat of flood disaster. Both Australia and China have taken many measures to remediate the damaged ecosystems but none of them have been proven fully effective. In our proposal, the patented soft-dam coastal reservoir will be built at the river mouths to uphold the river runoff lost to the sea. The preliminary study shows that with the use of the coastal reservoirs, the river runoff and water supply in these two basins can be significantly increased and the water quality can also be improved. This is because 1) there exists an adequate amount of good quality water in these two river mouths, especially during the flood seasons; 2) it is technically and economically feasible to develop the storm water, relative to other methods such as long distance water diversion & transportation and seawater desalination; 3) the patented technology uses the natural resources in a sustainable and environmental friendly way to the ecosystem.

Traditionally plasma systems have required high operating power, low operating pressure and are relatively large in size, limiting the technology to mostly immobile, large-scale industrial applications. In recent years, microplasma devices have emerged due especially to improvements in microchip fabrication technology. Microplasmas improve on plasma performance, allow for atmospheric operation, permit portability and significantly reduce both the cost of manufacturing and the cost of electrical power. These developments allow for technological improvements in fields such as displays, medicine, alternate energy and chemical analysis. This review will first introduce the concept of man-made plasmas and the distinctive characteristics of microplasmas, then discuss some of the most recent patents of microplasmas with specific regard to devices possessing a microcavity. These patents relate to device types, fabrication improvements and the various applications of microplasma technology.

Silicon on Insulator (SOI) waveguides are attracting considerable attention in recent years, and the devices based on these optical waveguides are important to realize many modern optical signal processing systems. The main driving forces behind these devices are the technological improvements in exploiting the non-linear optical phenomenon and their compatibility with CMOS devices. Although all optical signal processing devices have been investigated intensively, the chip-scale solution provided by the silicon photonics is the most promising. Silicon photonic devices are finding their applications in telecommunication transmission systems and biomedical instruments and in the new generation of high performance computing systems. Recent progress in patents all over the globe, along with important technological developments in this field are reviewed.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by different engineering methods, processed and techniques involved.