Novel Algorithm for Radon Real-Time Measurements with a Pixelated Detector

Nowadays, radon gas exposure is considered one of the main health concerns for the population because, by carrying about half the total dose due to environmental radioactivity, it is the second cause of lung cancer after smoking. Due to a relatively long half-life of 3.82 days, the chemical inertia and since its parent Ra-226 is largely diffuse on the earthrgb]0,0,1’s crust and especially in the building materials, radon can diffuse and potentially saturate human habitats, with a concentration that can suddenly change during the 24 h day depending on temperature, pressure, and relative humidity. For such reasons, `real-time’ measurements performed by an active detector, possibly of small dimensions and a handy configuration, can play an important role in evaluating the risk and taking the appropriate countermeasures to mitigate it. In this work, a novel algorithm for pattern recognition was developed to exploit the potentialities of silicon active detectors with a pixel matrix structure to measure radon through the α emission, in a simple measurement configuration, where the device is placed directly in air with no holder, no collection filter or electrostatic field to drift the radon progenies towards the detector active area. This particular measurement configuration (dubbed as bare) requires an α/β-discrimination method that is not based on spectroscopic analysis: as the gas surrounds the detector the α particles are emitted at different distances from it, so they lose variable energy amount in air depending on the traveled path-length which implies a variable deposited energy in the active area. The pixels matrix structure allows overcoming this issue because the interaction of α, β and γ particles generate in the active area of the detector clusters (group of pixels where a signal is read) of different shape and energy dispersion. The novel algorithm that exploits such a phenomenon was developed using a pixelated silicon detector of the TimePix family with a compact design. An α(Am-241) and a β(Sr-90) source were used to calibrate the algorithm and to evaluate its performances in terms of β rejection capability and α recognition efficiency. Successively, the detector was exposed to different radon concentrations at the ENEA-INMRI radon facility in `bare’ configuration, in order to check the linearity of the device response over a radon concentration range. The results for this technique are presented and discussed, highlighting the potential applications especially the possibility to exploit small and handy detectors to perform radon active measurements in the simplest configuration.

A Novel Wideband Coplanar Waveguide (CPW) Fed Antenna for Energy Harvesting at 2.45 GHz

Conversion of electric power from a high voltage to a low voltage causes power losses that also require efficient circuit design techniques to be implemented for durability of a system. Energy harvesting techniques have been implemented to cater to the power demand of low power electronic devices using electromagnetic, electrostatic, and other related technologies. This paper represents the compact design of an antenna system tuned at 2.45 GHz for radio frequency energy harvesting applications. The simulation results achieve a better gain of 5.4 dB along with enhanced radiation patterns. Impedance matching for 50 Ohm is implemented using a high frequency structure simulator (HFSS). The results of the antenna gain, VSWR, and radiation efficiency are compared with the literature. Furthermore, the size of the antenna system has great significance in medical and military related applications; this aspect is also considered in this design and overall, a 20 mm × 37 mm compact antenna is achieved by using mm wave considerations. This antenna design can be embedded in the wireless sensor network (WSN), RFID, and IoT related application to generate the required power required. Mostly, WSN nodes currently use traditional batteries that need to be replaced after some time. As in most cases, WSN nodes are scattered in wide geographical areas, so maintaining the power to these systems becomes challenging. RF energy harvesting provides a solution in these cases where wind, vibration, and solar sources are scarce. The simulated impedance bandwidth is found to range from 1.1 GHz to 5.2 GHz within the acceptable VSWR values.

Gain Enhancement of Double-Slot Vivaldi Antenna using Corrugated Edges and Semicircle Director for Microwave Imaging Application

Microwave imaging, such as images for radiological inspection in the medical profession, is one of the applications utilized in ultra-wideband (UWB) frequency ranges. The Vivaldi antenna is one of the most popular antennas for this purpose. The antenna is utilized because of its simple, lightweight, and compact design, as well as its excellent efficiency and gain capabilities. In this work, we present a high-gain Vivaldi antenna for microwave imaging applications. The proposed Vivaldi antenna is designed using a double-slot structure method with the addition of corrugated edges and a semicircle director aimed at improving the gain. The antenna is designed to operate at frequencies ranging from 3.1 to 10.6 GHz. Based on the modeling findings, the suggested antenna attain a bandwidth of 7.5 GHz with operating frequencies from 3.1 GHz to 10.6 GHz for a VSWR of less than two. In comparison to a typical single slot antenna, the suggested antenna provides a substantial boost in gain performance. The increase in gain is proportional to the frequency of operation. The constructed antenna has a lower bandwidth than the simulated one, with operating frequencies of 3.5 GHz – 3.75 GHz and 4.25 – 10.89 GHz, respectively, and useable bandwidths of 250 MHz and 6.64 GHz. All these results suggest that the antenna is suitable for microwave imaging applications.

Bio-Compatible Sensor for Middle Ear Pressure Monitoring on a Bio-Degradable Substrate

Hypotension in the middle ear can cause serious diseases and hearing disorders. Until now, pressure in the middle ear is measured indirectly by using the impedance of the tympanic membrane (tympanometry). Direct methods are just described in scientific studies and would be harmful in clinical routine. Here, we demonstrate a bio-compatible pressure sensor, which can resolve pressure changes in the range of −7.5 kPa up to +7.5 kPa, and due to its compact design (area of 2 × 4 mm2), can be directly implanted in the human middle ear. Furthermore, the read-out of the pressure sensor can be conveniently done using wireless data communication technologies employing a plate capacitor with an elastic dielectric for pressure monitoring and a planar coil. Thus, our sensor allows for direct pressure measurements in the middle ear, avoiding additional surgeries after device implantation.

Implementation of PI and MPC-Based Speed Controllers for a Drive with Elastic Coupling on a PLC Controller

This paper presents some of the issues related to the implementation of advanced control structures (PI controller with additional feedback, Model Predictive Controller) for drives with elastic coupling on a programmable logic controller (PLC). The predominant solutions to electric drive control include the use of rapid prototyping cards, signal processors or programmable matrices. Originally, PLC controllers were used to automate sequential processes, but for several years now, a trend related to their implementation for advanced control objects can be observed. This is mainly due to their compact design, immunity to disturbances and standard programming languages. The following chapters of the paper present the mathematical model of the drive and describe the implementation of the proposed control structures. A PI controller with additional feedback loops and a predictive controller are taken into consideration. Their impact on the CPU load was analysed, and the work was summarised by a comprehensive experimental study. The presented results confirm that it is possible to implement advanced control structures on a PLC controller for drives with elastic coupling while maintaining a sufficiently low load on its CPU.

Developing portable widefield fundus camera for teleophthalmology: Technical challenges and potential solutions

A portable, low cost, widefield fundus camera is essential for developing affordable teleophthalmology. However, conventional trans-pupillary illumination used in traditional fundus cameras limits the field of view (FOV) in a snapshot image, and frequently requires pharmacologically pupillary dilation for reliable examination of eye conditions. This minireview summarizes recent developments in alternative illumination approaches for widefield fundus photography. Miniaturized indirect illumination has been used to enable compact design for developing low cost, portable, widefield fundus camera. Contact mode trans-pars-planar illumination has been validated for ultra-widefield fundus imaging of infant eyes. Contact-free trans-pars-planar illumination has been explored for widefield imaging of adult eyes. Trans-palpebral illumination has been also demonstrated in a smartphone-based widefield fundus imager to foster affordable teleophthalmology.

Advancements in Battery Technologies of Electric Vehicle

The Automotive Industry has undergone a huge revolution – Electric Vehicles! Electric cars are growing fast and the demand for them is increasing all around the world, thanks to the more and improved choice, reduced prices, and enhancing battery technology. Introduced more than 100 years ago, electric vehicles have gone through a tremendous amount of advancement. This paper reviews the current major challenges faced by the Electric Vehicle Industry along with possible solutions to overcome them. Although electric vehicles have come a long way, the battery used in the vehicles needs to be further explored to harness maximum energy with a compact design. Electric vehicles should soon be able to compete with combustion engine vehicles in every aspect. Also, this paper reviews alternative materials for electrodes and batteries to make charging faster and reliable than ever. This paper envisages few concepts that could revolutionize Automobile Industry further in the future.