Small Loop Antenna System Design for Radio Direction Finding

In this literature, a low-cost small loop antenna is developed for radio direction finding. It consists of two coupled rectangular counter-wiring loop antennas. A signal-processing circuit is developed also for demodulated outputs. A single rectangular loop antenna is discussed first for illustrating the receiving characteristics and then the proposed two coupled rectangular counter-wiring loop antennas are designed for radio direction finding. Measurements give a large linear detecting range. It is ready for Omni-directional application using another two coupled loop antennas and can be used as a tracking control device.

A Robust and Wearable Triboelectric Tactile Patch as Intelligent Human-Achine Interface

The human–machine interface plays an important role in the diversified interactions between humans and machines, especially by swaping information exchange between human and machine operations. Considering the high wearable compatibility and self-powered capability, triboelectric-based interfaces have attracted increasing attention. Herein, this work developed a minimalist and stable interacting patch with the function of sensing and robot controlling based on triboelectric nanogenerator. This robust and wearable patch is composed of several flexible materials, namely polytetrafluoroethylene (PTFE), nylon, hydrogels electrode, and silicone rubber substrate. A signal-processing circuit was used in this patch to convert the sensor signal into a more stable signal (the deviation within 0.1 V), which provides a more effective method for sensing and robot control in a wireless way. Thus, the device can be used to control the movement of robots in real-time and exhibits a good stable performance. A specific algorithm was used in this patch to convert the 1D serial number into a 2D coordinate system, so that the click of the finger can be converted into a sliding track, so as to achieve the trajectory generation of a robot in a wireless way. It is believed that the device-based human–machine interaction with minimalist design has great potential in applications for contact perception, 2D control, robotics, and wearable electronics.

Development of a Physical Separation Route for the Concentration of Base Metals from Old Wasted Printed Circuit Boards

Wastes from old electronic devices represent a significant part of the electronic scrap generated in developing countries, being commonly sold by collectors as low-value material to recycling hubs abroad. Upgrading the quality of this waste type could drive the revenue of recyclers, and thus, boost the recycling market. On this basis, this study investigated the possibility of concentrating metals from old wasted printed circuit boards through a physical separation-based route. Preparation of samples comprised fragmentation, size classification, density, and magnetic separation steps, followed by chemical and macro composition analysis. Cu, Al, Fe, and Sn constituted the major metals encountered in the scraps, including some peak concentrations of Zn, Sb, Pb, Ba, and Mn. Four distinct concentrate products could be obtained after suitable processing: (a) a light fraction composed of plastics and resins; (b) an aluminum concentrate; (c) a magnetic material concentrate, containing mainly iron; (d) a final concentrate containing more than 50% in mass of copper and enriched with nonferrous metals. Preliminary evidence showed that further processes, like the separation of copper wires through drumming, can potentially improve the effectiveness of the proposed processing circuit and should guide future works.

Development of a combined processing technology for low-sulfide gold-bearing ores

This paper presents the results of laboratory dressability studies for low-sulfide gold-bearing ores using combined processing and subsequent oxidation leaching of the resulting combined concentrate. According to the current raw materials processing circuit used at the Sekisovskoye deposit, gravity concentration experiments were first carried out using the following laboratory equipment: a Knelson KSMD 3 centrifugal concentrator, an SKO-05 concentration table, and a two-chamber diaphragm jigging machine (i.e., OML by TsNIGRI). A significant portion (0.5 to 1.0 g/t) of the gold remains in the gravity concentration tailings. Subsequent flotation experiments for the tailings suggest that additional gold recovery is possible. The gold content in the final flotation tailings was in the range of 0.15–0.25 g/t. The final gold recovery in the combined process was therefore 93.7–96.5 %. The subsequent sorption cyanidation of the concentrate according to the current processing circuit allows depositing an average of 75.0–80.0 % Au on the coal. At the same time, the residual gold content in the sorption leaching tailings is significant and amounts to 3.6–7.5 g/t. The preliminary oxidation experiments for the concentrate slurry indicate the possibility of a more complete gold recovery with subsequent leaching, including sorption leaching. The residual gold content in the cakes was measured at 0.7–1.5 g/t, which ultimately yielded 95–96 % recovery at the leaching stage. The research was completed with the financial support of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan under grant No. АР05130143.

Dynamic FPAA-based Mixed-Signal Processing Circuit for Thin-Film CdTe/Lead-Free Perovskite Photodetectors

New photodetector structure combining thinned CdTe film with lead-free perovskite photoelectric film was produced and investigated. This setting of the CdTe thickness results in photodetector parameters’ competitiveness to the state-of-the-art in the field of advanced photoelectric materials. The device shows a promising sensitivity of ~40 μA/W, maximum responsivity of 10.6 mA/W at 460 nm, equal rise and fall times of 30 ms, and high linearity (maximum linearization error is less than 0.6 %). However, the optoelectronic performance of CdTe/lead-free perovskite structures integrated with signal processing circuit remains unexplored. For this purpose, Field Programmable Analogue Array (FPAA)-based mixed-signal processing circuit is developed for pulse width modulated electrical signal with duty cycle controlled by the illumination degree of the detecting photoelement. This novel approach guarantees a smooth change of the electrical output at a smooth change of the input illumination between the light and dark switching states and can be practically applied as a precise position detector of moving objects. The paper represents a synergistic connection between microelectronics, electronics, and signal technology.

Design And Implementation of An Ultra-Low Power Bose Chaudhuri Hocquenghem Encoding Based Body Channel Communication For Medical Applications

This paper proposes the Bose–Chaudhuri–Hocquenghem (BCH) encoding based Body Channel Communication (BCC) for medical applications by ultra-low power consumption. The transmitter uses channel of 1-100 MHz frequency to enhance the transmitter frequency and time domain properties. The BCH based BCC transmitter uses two stage low power analog processing circuit and digital information restoration circuit. The analog processing circuit consists of capacitor coupled adjustable preamplifier. In addition to that a body channel communication (BCC) transceiver with BCH codes modulation is proposed. In the BCC transceiver side, sensed data are encoded into BCH code format, and then the chosen BCH codes restrict the maximum consecutive identical digit (CID) to rise the data transmission rate. In the BCC receiver side, we use an analog front-end (AFE) circuit board to amplify the attenuated signal from the transmitter and restore the signal to the digital waveform. After the 8x oversampling sampler and vote integrator recovery the clock and data, the BCH code demodulator demodulates the original data. The proposed BCC transceiver has higher data reliability because of the orthogonal characteristic of BCH codes. Moreover, the proposed BCH code concatenated method strengthens the jitter tolerance and improve the code rate. The proposed BCC transceiver was verified on a field-programmable gate array (FPGA) board. The Proposed Data transceiver achieves data rate of 100 Mbps, Also, the BER value is < 10− 6 and < 10− 5 at 60 Mbps and 100 Mbps, respectively.

A Computational Model for Pain Processing in the Dorsal Horn Following Axonal Damage to Receptor Fibers

Computational modeling of the neural activity in the human spinal cord may help elucidate the underlying mechanisms involved in the complex processing of painful stimuli. In this study, we use a biologically-plausible model of the dorsal horn circuitry as a platform to simulate pain processing under healthy and pathological conditions. Specifically, we distort signals in the receptor fibers akin to what is observed in axonal damage and monitor the corresponding changes in five quantitative markers associated with the pain response. Axonal damage may lead to spike-train delays, evoked potentials, an increase in the refractoriness of the system, and intermittent blockage of spikes. We demonstrate how such effects applied to mechanoreceptor and nociceptor fibers in the pain processing circuit can give rise to dramatically distinct responses at the network/population level. The computational modeling of damaged neuronal assemblies may help unravel the myriad of responses observed in painful neuropathies and improve diagnostics and treatment protocols.

Electret Nanogenerators for Self-Powered, Flexible Electronic Pianos

Traditional electronic pianos mostly adopt a gantry type and a large number of rigid keys, and most keyboard sensors of the electronic piano require additional power supply during playing, which poses certain challenges for portable electronic products. Here, we demonstrated a fluorinated ethylene propylene (FEP)-based electret nanogenerator (ENG), and the output electrical performances of the ENG under different external pressures and frequencies were systematically characterized. At a fixed frequency of 4 Hz and force of 4 N with a matched load resistance of 200 MΩ, an output power density of 20.6 mW/cm2 could be achieved. Though the implementation of a signal processing circuit, ENG-based, self-powered pressure sensors have been demonstrated for self-powered, flexible electronic pianos. This work provides a new strategy for electret nanogenerators for self-powered sensor networks and portable electronics.