scholarly journals A Low-Power CMOS Wireless Acoustic Sensing Platform for Remote Surveillance Applications

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 178
Author(s):  
Yong Wang ◽  
Ranran Zhou ◽  
Zhenyue Liu ◽  
Bingbo Yan
Keyword(s):  
Low Power ◽  
Maximum Output Power ◽  
Audio Signal ◽  
Digital Signal ◽  
Maximum Output ◽  
Acoustic Sensing ◽  
Sensing Platform ◽  
Remote Surveillance ◽  
Standby Mode ◽  
Surveillance Applications

A low-power wireless acoustic sensing platform for remote surveillance applications based on a 180 nm CMOS technology is proposed in this paper. The audio signal, which is acquired by a microphone, is first amplified and filtered. Then, the analog signal is converted to a digital signal by a 10-bit analog-to-digital converter (ADC). A digital automatic gain control module is integrated to obtain an optimal input of the ADC. The digital signal is modulated and transmitted at the 433 MHz ISM band after being repacked and encoded. To save power for portable applications, the chip switches to standby mode when no audio is detected. The wireless sensing platform occupies a chip area of 1.76 mm 2 . The supply voltage is 2.5 V for the power amplifier and 1.8 V for other circuits. The measured maximum output power is 5.7 dBm and the transmission distance is over 500 m for real application scenarios. The chip consumes 25.1 mW power in normal work mode and 0.058 mW in standby mode. Compared to existing wireless acoustic sensors, the proposed wireless acoustic sensing platform can achieve features such as compactness, power efficiency, and reliability.

scholarly journals A Fault Diagnosis Mechanism with Power Generation Improvement for a Photovoltaic Module Array

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 598
Author(s):  
Kuei-Hsiang Chao ◽  
Pei-Lun Lai
Keyword(s):  
Output Power ◽  
Digital Signal Processor ◽  
Maximum Output Power ◽  
Diagnostic Algorithm ◽  
Digital Signal ◽  
Photovoltaic Module ◽  
Maximum Output ◽  
Point Tracking ◽  
Pv Module ◽  
Power Operation

This paper aims to develop an online diagnostic mechanism, doubling as a maximum power point tracking scheme, for a photovoltaic (PV) module array. In case of malfunction or shadow event occurring to a PV module, the presented diagnostic mechanism is enabled, automatically and immediately, to reconfigure a PV module array for maximum output power operation under arbitrary working conditions. Meanwhile, the malfunctioning or shaded PV module can be located instantly by this diagnostic mechanism according to the array configuration, and a PV module replacement process is made more efficient than ever before for the maintenance crew. In this manner, the intended maximum output power operation can be resumed as soon as possible in consideration of a minimum business loss. Using a particle swarm optimization (PSO)-based algorithm, the PV module array is reconfigured by means of switch manipulations between modules, such that a load is supplied with the maximum amount of output power. For compactness, the PSO-based online diagnostic algorithm is implemented herein using a TMS320F2808 digital signal processor (DSP) and is experimentally validated as successful to identify a malfunctioning PV module at the end of this work.

Characterization of microwave-sintered ceramic composites

1993 ◽  
Vol 51 ◽  
pp. 1136-1137
Author(s):  
X. Zhang ◽  
Y. Pan ◽  
T.T. Meek
Keyword(s):  
Matrix Material ◽  
Maximum Output Power ◽  
Ceramic Matrix Composite ◽  
Ceramic Composites ◽  
Processing Technique ◽  
Structure Characterization ◽  
Alumina Powder ◽  
Maximum Output ◽  
Sintered Ceramic

Industrial microwave heating technology has emerged as a new ceramic processing technique. The unique advantages of fast sintering, high density, and improved materials properties makes it superior in certain respects to other processing methods. This work presents the structure characterization of a microwave sintered ceramic matrix composite.Commercial α-alumina powder A-16 (Alcoa) is chosen as the matrix material, β-silicon carbide whiskers (Third Millennium Technologies, Inc.) are used as the reinforcing element. The green samples consisted of 90 vol% Al2O3 powder and 10 vol% ultrasonically-dispersed SiC whiskers. The powder mixture is blended together, and then uniaxially pressed into a cylindrical pellet under a pressure of 230 MPa, which yields a 52% green density. The sintering experiments are carried out using an industry microwave system (Gober, Model S6F) which generates microwave radiation at 2.45 GHz with a maximum output power of 6 kW. The composites are sintered at two different temperatures (1550°C and 1650°C) with various isothermal processing time intervals ranging from 10 to 20 min.

scholarly journals One-Step Preparation of Biochar Electrodes and Their Applications in Sediment Microbial Electrochemical Systems

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 508
Author(s):  
Kui You ◽  
Zihan Zhou ◽  
Chao Gao ◽  
Qiao Yang
Keyword(s):  
Output Power ◽  
Electrode Materials ◽  
Maximum Output Power ◽  
Composite Cathode ◽  
Maximum Output ◽  
Electrochemical Systems ◽  
Composite Cathodes ◽  
One Step ◽  
Microbial Electrochemical Systems ◽  
Hot Melt

Biochar is a kind of carbon-rich material formed by pyrolysis of biomass at high temperature in the absence or limitation of oxygen. It has abundant pore structure and a large surface area, which could be considered the beneficial characteristics for electrodes of microbial electrochemical systems. In this study, reed was used as the raw material of biochar and six biochar-based electrode materials were obtained by three methods, including one-step biochar cathodes (BC 800 and BC 700), biochar/polyethylene composite cathodes (BP 5:5 and BP 6:4), and biochar/polyaniline/hot-melt adhesive composite cathode (BPP 5:1:4 and BPP 4:1:5). The basic physical properties and electrochemical properties of the self-made biochar electrode materials were characterized. Selected biochar-based electrode materials were used as the cathode of sediment microbial electrochemical reactors. The reactor with pure biochar electrode (BC 800) achieves a maximum output power density of 9.15 ± 0.02 mW/m2, which increases the output power by nearly 80% compared with carbon felt. When using a biochar/polyaniline/hot-melt adhesive (BPP 5:1:4) composite cathode, the output power was increased by 2.33 times. Under the premise of ensuring the molding of the material, the higher the content of biochar, the better the electrochemical performance of the electrodes. The treatment of reed powder before pyrolysis is an important factor for the molding of biochar. The one-step molding biochar cathode had satisfactory performance in sediment microbial electrochemical systems. By exploring the biochar-based electrode, waste biomass could be reused, which is beneficial for the environment.

scholarly journals Novel Heat-Mitigating Chip-on-Probe for Brain Stimulation Behavior Experiments

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7334
Author(s):  
Seongwoog Oh ◽  
Jungsuek Oh
Keyword(s):  
Brain Stimulation ◽  
Heat Sink ◽  
Transmission Loss ◽  
Maximum Output Power ◽  
Circuit Board ◽  
Oxide Semiconductor ◽  
Normal Operation ◽  
Cmos Process ◽  
Maximum Output ◽  
The Brain

This paper proposes a novel design for a chip-on-probe with the aim of overcoming the heat dissipation effect during brain stimulations using modulated microwave signals. The temperature of the stimulus chip during normal operation is generally 40 °C–60 °C, which is sufficient to cause unintended temperature effects during stimulation. This effect is particularly fatal in brain stimulation applications that require repeated stimulation. This paper proposes, for the first time, a topology that vertically separates the stimulus chip generating the stimulus signal and the probe delivering the signal into the brain to suppress the heat transfer while simultaneously minimizing the radio frequency (RF) transmission loss. As the proposed chip-on-probe should be attached to the head of a small animal, an auxiliary board with a heat sink was carefully designed considering the weight that does not affect the behavior experiment. When the transition structures are properly designed, a heat sink can be mounted to maximize the cooling effect, reducing the temperature by more than 13 °C in a simulation when the heat generated by the chip is transferred to the brain, while the transition from the chip to the probe experiences a loss of 1.2 dB. Finally, the effectiveness of the proposed design is demonstrated by fabricating a chip with the 0.28 μm silicon-on-insulator (SOI) complementary metal–oxide–semiconductor (CMOS) process and a probe with a RT6010 printed-circuit board (PCB), showing a temperature reduction of 49.8 °C with a maximum output power of 11 dBm. In the proposed chip-on-probe device, the temperature formed in the area in contact with the brain is measured at 31.1 °C.

scholarly journals Study of the Properties of a Hybrid Piezoelectric and Electromagnetic Energy Harvester for a Civil Engineering Low-Frequency Sloshing Environment

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 391
Author(s):  
Nan Wu ◽  
Yuncheng He ◽  
Jiyang Fu ◽  
Peng Liao
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Civil Engineering ◽  
Maximum Output Power ◽  
Low Frequency ◽  
Electromagnetic Energy ◽  
Maximum Output ◽  
Piezoelectric Film ◽  
Hybrid Energy ◽  
Level Height

In this paper a novel hybrid piezoelectric and electromagnetic energy harvester for civil engineering low-frequency sloshing environment is reported. The architecture, fabrication and characterization of the harvester are discussed. The hybrid energy harvester is composed of a permanent magnet, copper coil, and PVDF(polyvinylidene difluoride) piezoelectric film, and the upper U-tube device containing a cylindrical fluid barrier is connected to the foundation support plate by a hinge and spring. The two primary means of energy collection were through the vortex street, which alternately impacted the PVDF piezoelectric film through fluid shedding, and the electromotive force (EMF) induced by changes in the magnetic field position in the conducting coil. Experimentally, the maximum output power of the piezoelectric transformer of the hybrid energy harvester was 2.47 μW (circuit load 270 kΩ; liquid level height 80 mm); and the maximum output power of the electromagnetic generator was 2.72 μW (circuit load 470 kΩ; liquid level height 60 mm). The low-frequency sloshing energy collected by this energy harvester can drive microsensors for civil engineering monitoring.

Low-Power Digital Signal Processing Using Approximate Adders

2013 ◽  
Vol 32 (1) ◽  
pp. 124-137 ◽  
Author(s):  
Vaibhav Gupta ◽  
Debabrata Mohapatra ◽  
Anand Raghunathan ◽  
Kaushik Roy
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Low Power ◽  
Digital Signal

Low-power, open-path mobile sensing platform for high-resolution measurements of greenhouse gases and air pollutants

2015 ◽  
Vol 119 (1) ◽  
pp. 153-164 ◽  
Author(s):  
Lei Tao ◽  
Kang Sun ◽  
David J. Miller ◽  
Dan Pan ◽  
Levi M. Golston ◽  
...  
Keyword(s):  
High Resolution ◽  
Greenhouse Gases ◽  
Low Power ◽  
Air Pollutants ◽  
Mobile Sensing ◽  
Open Path ◽  
Sensing Platform

scholarly journals The Investigation on Ultrafast Pulse Formation in a Tm–Ho-Codoped Mode-Locking Fiber Oscillator

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3460
Author(s):  
Jingcheng Shang ◽  
Yizhou Liu ◽  
Shengzhi Zhao ◽  
Yuefeng Zhao ◽  
Yuzhi Song ◽  
...  
Keyword(s):  
Maximum Output Power ◽  
Single Pulse ◽  
Mode Locking ◽  
Maximum Output ◽  
Polarization Rotation ◽  
Nonlinear Polarization ◽  
Soliton Pulse ◽  
Proper Design ◽  
Nonlinear Polarization Rotation ◽  
Pulse Formation

We experimentally investigate the formation of various pulses from a thulium–holmium (Tm–Ho)-codoped nonlinear polarization rotation (NPR) mode-locking fiber oscillator. The ultrafast fiber oscillator can simultaneously operate in the noise-like and soliton mode-locking regimes with two different emission wavelengths located around 1947 and 2010 nm, which are believed to be induced from the laser transition of Tm3+ and Ho3+ ions respectively. When the noise-like pulse (NLP) and soliton pulse (SP) co-exist inside the laser oscillator, a maximum output power of 295 mW is achieved with a pulse repetition rate of 19.85-MHz, corresponding to a total single pulse energy of 14.86 nJ. By adjusting the wave plates, the fiber oscillator could also deliver the dual-NLPs or dual-SPs at dual wavelengths, or single NLP and single SP at one wavelength. The highest 61-order harmonic soliton pulse and 33.4-nJ-NLP are also realized respectively with proper design of the fiber cavity.

Sign in / Sign up

Export Citation Format

Share Document