Designing a Monitoring System to Observe the Innovative Single-Wire and Wireless Energy Transmitting Systems in Explosive Areas of Underground Mines

Suspended monorails are a common mode of transportation for materials and personnel in underground mines. The goal of the EU-funded project “Innovative High Efficiency Power System for Machines and Devices, Increasing the Level of Work Safety in Underground Mining Excavations (HEETII)” is to introduce a single-wire energy transmission system combined with a capacitive-coupling-based wireless transmission system to power the suspended tractor, along with a monitoring system that will monitor the energy network and additional environmental parameters of the mine. Additionally, the monitoring system acts as the wireless communication backbone, allowing for data transmission to surface headquarters, where the data are processed and logged in a central database. This enables operators to detect and take preemptive measures to prevent potential hazards in the mine, improving the overall efficiency of the energy transmission system. This paper describes the additional considerations required for electrical systems in underground mines with potentially explosive atmospheres, as well as the design of the energy transmission system and the monitoring system.

LDLA14: a 14 Gbps optical transceiver ASIC in 55 nm for NICA multi purpose detector project

This paper presents the design and test results of a 14 Gbps optical transceiver ASIC (LDLA14) fabricated in a 55 nm CMOS technology for NICA Multi Purpose Detector (MPD) project. The LDLA14 is a single-channel bidirectional (1Tx + 1Rx) optical transceiver ASIC, including a Laser Driver (LD) module and a Limiting Amplifier (LA) module. It would drive the Vertical Cavity Surface Emitting Laser (VCSEL) of Transmitter Optical Sub-Assembly (TOSA) and receive signals from Photo Diode (PD) of Receiver Optical Sub-Assembly (ROSA), respectively. In the LDLA14, a novel structure of capacitive coupling pre-emphasis is proposed in the output driver of LD to obtain peaking effect without sacrifice the modulation current swing. A shared inductor technology and a Continuous Time Linear Equalizer (CTLE) pre-emphasis structure are added in the output buffer of LA to improve the quality of the output eye diagram. The dimension of LDLA14 is 1.5 mm × 1.3 mm, and the power consumption is 178 mW. The Peak-to-Peak Jitter (PPJ) and Root-Mean-Square Jitter (RMSJ) of the 14 Gbps optical eye diagram of LD in the Tx direction are 22.5 ps and 3.5 ps, respectively. The PPJ and RMSJ of the 14 Gbps electrical eye diagram of LA in the Rx direction are 23.1 ps and 4.7 ps, respectively. The BER tests have been conducted in Tx, Rx directions and the Tx-Rx loop condition, and the BER less than 10−12 is achieved in all tests.

Optimal Solutions for Underwater Capacitive Power Transfer

Capacitive power transfer (CPT) has attracted attention for on-road electric vehicles, autonomous underwater vehicles, and electric ships charging applications. High power transfer capability and high efficiency are the main requirements of a CPT system. This paper proposes three possible solutions to achieve maximum efficiency, maximum power, or conjugate-matching. Each solution expresses the available load power and the efficiency of the CPT system as functions of capacitive coupling parameters and derives the required admittance of the load and the source. The experimental results demonstrated that the available power and the efficiency decrease by the increasing of the frequency from 300 kHz to 1 MHz and the separation distance change from 100 to 300 mm. The maximum efficiency solution gives 83% at 300 kHz and a distance of 100 mm, while the maximum power solution gives the maximum normalized power of 0.994 at the same frequency and distance. The CPT system can provide a good solution to charge electric ships and underwater vehicles over a wide separation distance and low-frequency ranges.

High-Efficiency Multi-Sensor System for Chair Usage Detection

Recognizing Activities of Daily Living (ADL) or detecting falls in domestic environments require monitoring the movements and positions of a person. Several approaches use wearable devices or cameras, especially for fall detection, but they are considered intrusive by many users. To support such activities in an unobtrusive way, ambient-based solutions are available (e.g., based on PIRs, contact sensors, etc.). In this paper, we focus on the problem of sitting detection exploiting only unobtrusive sensors. In fact, sitting detection can be useful to understand the position of the user in many activities of the daily routines. While identifying sitting/lying on a sofa or bed is reasonably simple with pressure sensors, detecting whether a person is sitting on a chair is an open problem due to the natural chair position volatility. This paper proposes a reliable, not invasive and energetically sustainable system that can be used on chairs already present in the home. In particular, the proposed solution fuses the data of an accelerometer and a capacitive coupling sensor to understand if a person is sitting or not, discriminating the case of objects left on the chair. The results obtained in a real environment setting show an accuracy of 98.6% and a precision of 95%.

Bandwidth Control of Loop Type Frequency Selective Surfaces Using Dual Elements in Various Arrangements

Frequency-selective surfaces (FSSs) have applications across multiple disciplines due to their unique electromagnetic properties. This paper investigates the use of both rounded square loops (RSLs), and simple loop type dual elements arranged in unique patterns, to control the transmission and reflection bandwidth and resonant frequencies over KU and K frequency bands supported by equivalent circuit models (ECMs). The FSSs were fabricated using laser engraving to create conductive loop type elements on a thin, flexible and optically transparent Mylar substrate (relative permittivity of 2.7 and thickness of 65m). The frequency response of the surfaces are controlled through the element self-inductance and capacitive coupling with neighbouring elements. This work shows that different arrangements result in the formation of multiple distinct resonances. The theoretical and experimental results were in good agreement where rounded squares and dual element arrays were employed to create broadband and multiband band-stop FSSs. A polarization sensitive surface exhibited stop-bands at 12GHz and 16GHz in transverse electric polarization and a stop-band at 14.4GHz in transverse magnetic polarization. This technique can be applied to any periodic array through careful selection of the individual elements in the array, as well as their arrangement.

Different Setup of Capacitive Coupling Protection System on Mild Steel

A Capacitive Coupling Corrosion Protection (CCCP) technology based on coupler pads was investigated. The layout of the coupler pads on the mild steel surface was studied to get the best outdoor corrosion protection. A square wave of current/voltage is supplied to the steel surface for 72 hours via a copper coupler pad in three arrangements, i.e., single, double-sided, and opposite configurations. The efficiency of the CCCP configuration was assessed by measuring electrical current consumption, weight loss, and post-experimental surface morphology observations. It is found that the current consumption of 600 μA/cm2 in the double-sided configuration is practically stable. The lowest weight loss and clean surface morphology also prove that the double-sided configuration can improve the corrosion protection of mild steel. It was discovered that by employing more coupling pads on both sides of the metal sheet, the excessive positive charge capable of producing oxidation of mild steel could be easily discharged.

Influence of external parameters on RF inductive discharge plasma characteristics

Systematic experimental studies of the electron density and temperature, the efficiency of RF power coupling to the RF inductive discharge plasma have been carried out in the pressure range of helium, neon, argon, and krypton 0.1 – 133 Pa, at an RF generator power of 100 – 500 W and frequencies of 2, 4 and 13.56 MHz. It is shown that the electron density reaches a maximum, and the temperature reaches a minimum in the pressure range 1.33 – 13.3 Pa. Taking into account the presence of a parasitic capacitive coupling between the inductor and the plasma, which forms the capacitive channel of RF power input, makes it possible to conclude that the maximum values of the electron density were observed at the pressure at which the power input through the inductive channel is maximal. At pressures of the order of 0.133 Pa and below, an increase in the electron temperature is observed in the peripheral part of the discharge. Numerical modeling by the PIC method shows that one of the reasons is the formation of a directed azimuthal motion of electrons in the region of the skin layer. As the pressure increases, a transition occurs from the nonlocal to the local electron kinetics, which is reflected in the ratio between the electron temperature in the peripheral and central parts of the discharge.

Vm-related extracellular potentials observed in red blood cells

Even in nonexcitable cells, the membrane potential Vm is fundamental to cell function, with roles from ion channel regulation, development, to cancer metastasis. Vm arises from transmembrane ion concentration gradients; standard models assume homogeneous extracellular and intracellular ion concentrations, and that Vm only exists across the cell membrane and has no significance beyond it. Using red blood cells, we show that this is incorrect, or at least incomplete; Vm is detectable beyond the cell surface, and modulating Vm produces quantifiable and consistent changes in extracellular potential. Evidence strongly suggests this is due to capacitive coupling between Vm and the electrical double layer, rather than molecular transporters. We show that modulating Vm changes the extracellular ion composition, mimicking the behaviour if voltage-gated ion channels in non-excitable channels. We also observed Vm-synchronised circadian rhythms in extracellular potential, with significant implications for cell–cell interactions and cardiovascular disease.

High Magnetoelectric Coupling of Metglas and P(VDF-TrFE) Laminates

Magnetoelectric (magnetic/piezoelectric) heterostructures bring new functionalities to develop novel transducer devices such as (wireless) sensors or energy harvesters and thus have been attracting research interest in the last years. We have studied the magnetoelectric coupling between Metglas films (2826MB) and poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) in a laminate structure. The metallic Metglas film itself served as bottom electrode and as top electrode we used an electrically conductive polymer, poly(3,4-ethylene-dioxythiophene): poly(styrene sulfonate) (PEDOT:PSS). Besides a direct electrical wiring via a graphite ink, a novel contactless readout method is presented using a capacitive coupling between the PEDOT: PSS layer and an electrode not in contact with the PEDOT:PSS layer. From the experimental result we determined a magnetoelectric coupling of 1445 V/(cm×Oe) at the magnetoelastic resonance of the structure, which is among the highest reported values for laminate structures of a magnetostrictive and a piezoelectric polymer layer. With the noncontact readout method, a magnetoelectric coupling of about 950 V/(cm×Oe) could be achieved, which surpasses previously reported values for the case of direct sample contacting. 2D laser Doppler vibrometer measurements in combination with FE simulations were applied to reveal the complex vibration pattern resulting in the strong resonant response.

Online and Offline Diagnosis of Motor Power Cables Based on 1D CNN and Periodic Burst Signal Injection

We introduce a new approach for online and offline soft fault diagnosis in motor power cables, utilizing periodic burst injection and nonintrusive capacitive coupling. We focus on diagnosing soft faults because local cable modifications or soft faults that occur without any indication while the cable is still operational can eventually develop into hard faults; furthermore, advance diagnosis of soft faults is more beneficial than the later diagnosis of hard faults, with respect to preventing catastrophic production stoppages. Both online and offline diagnoses with on-site diagnostic ability are needed because the equipment in the automated lines operates for 24 h per day, except during scheduled maintenance. A 1D CNN model was utilized to learn high-level features. The advantages of the proposed method are that (1) it is suitable for wiring harness cables in automated factories, where the installed cables are extremely short; (2) it can be simply and identically applied for both online and offline diagnoses and to a variety of cable types; and (3) the diagnosis model can be directly established from the raw signal, without manual feature extraction and prior domain knowledge. Experiments conducted with various fault scenarios demonstrate that this method can be applied to practical cable faults.