Condition based monitoring has become essential in maintaining and extending the health of high-speed rotating and reciprocating machinery. One effective approach to detect signs of potential failure of a rotating or reciprocating machine is to examine the wear debris in its lubricating oil. Recent patents and research articles on on-line wear debris detection in lubricating oil are reviewed in this paper, including electrical impedance detection, acoustic detection, optical detection, pressure detection, online x-ray spectrography, resonant frequency detection, and electrostatic charge detection. Advantages and limitations of each detection method are discussed.
We review some patents on the use of Ionic Polymer-Metal Composites (IPMCs) and its manipulation to be used by different application areas. The different IPMC structures patented the techniques to improve its efficiency, and their operation as sensor and/or actuator mode. Some advantages/disadvantages of the different structures presented in relation to other existing but not using the IPMC material are also pointed out. Some future perspectives for the application of IPMCs are also explored.
This article describes the theoretical basis, design and implementation of X-ray microdetectors based on scintillating materials and CMOS technology. The working principle of such microdetectors consists in the absorption of X-rays by scintillators, which produce visible light. The visible light is then detected and converted into electric signals by means of photodetectors. In order to understand such detectors, several issues related to its implementation are presented in this article, namely:
Production of X-rays and interaction between them and matter - the first step necessary to the detection of X-rays is that they must be absorbed by some material, in this case by a scintillator;
Radiation detectors - there are several types of detectors, namely: pn junctions, photoconductors, based on thermal effects and scintillators;
Fabrication of scintillator arrays - after the X-ray radiation is absorbed by a scintillator, this material emits visible light whose intensity is proportional to the total energy of the absorbed X-rays;
Optical interfaces between scintillators and photodetectors - the visible light generated by scintillators must arrive to the photodetectors, so, it is necessary to have an interface between the scintillators and the photodetectors that ideally does not introduce losses;
Photodetectors and interface electronics - the visible light is absorbed by the photodetectors and converted into electrical signals, which are finally converted into digital images by means of interface electronics. The article presents some promising patents on X-ray detectors based on scintillators and CMOS technology.
A wideband quasi-elliptical bandpass filter with enhanced reject-band performance is presented. The proposed bandpass filter utilizes a new asymmetric defected ground structure (DGS) under a pair of end-coupled microstrip line. The DGS consists of two square headed slots connected transversely with a rectangular slot. The DGS-microstrip resonator provides band-accept filtering characteristics. To be equivalent to the circuit DGS is demonstrated. The presented equivalent circuit shows both resonant and anti-resonant properties. The equivalent circuit parameters are extracted using the modeling method of proposed DGS. A better selectivity in lower transition band in comparison to upper transition band is observed in the frequency response. To improve the roll-off in upper transition band, a pole is created by putting an additional DGS unit under the same microstrip line. The combined structure shows bandpass characteristics with deep and wide stopband on both sides of the passband. The bandwidth and centre frequency of the filter is controlled by the dimensions of both DGS cells. The article presents some promising patents on Defected Ground Structure Resonators and Admittance J-Inverter.
This paper describes the continuous progress of amorphous (a-Si:H) and microcrystalline (μc-Si:H) silicon based thin film solar cells and discusses its present scenarios based on patents and open reviews. The efficiency of hydrogenated amorphous silicon (a-Si:H) thin film solar cells has gradually improved from 2.4% to 15.2% (stable 13.0%). The major advantages of a-Si:H solar cells are the multijunction device capability, bandgap tailoring, easy fabrication, large scale production and high optical absorption coefficient. But the important factor for higher stabilized efficiencies is light induced effect on a-Si:H based solar cells was first reported by Staebler and Wronski. The highest recorded stabilized efficiency in micromorph cell is 10.18%. Though a lot of improvements have been done yet it needs more investigation. However, the improvement of open circuit voltage (Voc) is reviewed that is done with wide bangdgap window layers (a-SiC:H, μc-SiO:H, nc-Si:H etc) and inserting buffer layers at p/i and i/n interfaces in a-Si:H solar cells. An achievement of higher short circuit current (Jsc) by light trapping scheme is also reviewed. The material search for good optical and electrical properties and the device design technology is an immense need for further improvements of a- Si:H solar cell performances which are also being discussed with analysis of most relevant patents.
Digital video decoding is a typical data-intensive video processing application. Currently, high throughput and real time processing are the fundamental demands of performance for video processing systems. With the development of various video standards, multi-standard applications have become another key feature. Thus, the high performance, low area cost and low power consumption make up the most important design targets when realizing video processing chips. Reconfigurable hardware architectures have been reviewed in this paper, which could meet the above requirements for multi-standard video decoders. Traditional reconfiguration methods usually decrease area cost by reconfiguring the interconnections among function units. A relatively new approach is dynamic reconfiguration, which could reconfigure hardware resources at runtime. Recently, a new method called Reconfigurable Video Coding (RVC) has come up, which is a library-based method to design a reconfigurable system for multi-standard video decoders. An overview of the methodologies for reconfigurable video processing system is shown in the paper, as well as case studies, which demonstrate the effectiveness of the design flow. The article presents some promising patents on design of reconfigurable architectures for multi-standards video decoder.
Online detection and classification of changing harmonic signal content are common issues in vehicle control, both regarding mechanical and electrical oscillations. This paper presents an overview of the most recent patents. In particular it shows an invention in which a fast and numerically efficient method is used. The well known signal correlation principle is applied to detect, in real time operation, instantaneous dominant oscillations in a time-varying (temporally-variant) harmonic signal.