A Novel Peak-Seek Algorithm Used in FBG Sensor Demodulation System for Vibration Monitoring

2012 ◽  
Vol 160 ◽  
pp. 135-139 ◽  
Author(s):  
Lin Jun Cai ◽  
Zheng Ying Li ◽  
Zhi Hao Tang ◽  
Wei Meng ◽  
Quan Liu
Keyword(s):  
High Speed ◽  
Dynamic Range ◽  
Mechanical Vibration ◽  
Optical Power ◽  
Vibration Monitoring ◽  
Practical Applications ◽  
Fbg Sensor ◽  
Collection Data ◽  
The Stability

The FBG sensor technologies used for real-time monitoring of the mechanical vibration have attracted more and more concerns from both academic and industrial domains. In practical applications, the vibration frequency of the equipments generally reach up to a few hundred to several thousand Hz, however, the existing FBG demodulator is incompetent to meet the actual requirements of vibration monitoring in terms of demodulation speed and algorithm structures. To solve this problem while achieving a higher accuracy at a relatively lower computation cost, a novel adaptive semi-peak-seek algorithm based on state machine is proposed, which can be divided into three parts including data collection, data analysis and data verification. The experiment result shows that for the demodulation speed of 2 KHz, we can reach a demodulation accuracy of 1pm and a static noise within ±2pm. On the basis of a long term test, the stability error that less than 2pm and the system dynamic range of 0~ -30db are concluded, and the measurement error with the optical power attenuation is limited to 4pm. Thus, the proposed algorithm is capable to meet the requirements of high-speed demodulation devices in terms of speed, precision, stability and anti-interference properties.

Experiment and Research of Using Fiber Bragg Grating to Monitor the Dynamic Response of Asphalt Concrete

2011 ◽  
Vol 97-98 ◽  
pp. 301-304 ◽  
Author(s):  
Ke Li ◽  
Jian Guang Xie
Keyword(s):  
Dynamic Response ◽  
Fiber Bragg Grating ◽  
Asphalt Concrete ◽  
High Speed ◽  
Load Test ◽  
Bragg Grating ◽  
Static Load Test ◽  
Practical Applications ◽  
Fbg Sensor ◽  
On The Road

Based on the fiber Bragg grating sensing technology, a FBG sensor is designed to monitor the dynamic response of asphalt concrete; the sensitivity coefficient of FBG sensor is 1.28pm/με. Through the static load test, the correlation between strain and wavelength variation is 0.1797µε/pm, after second packaged and embedded in SMA-13 asphalt concrete. The instantaneous impact on the road of high-speed vehicles is simulated by using drop hammer. The results are shown that the Sensor can satisfy the requirements of practical applications and succeed in monitoring the dynamic response of asphalt concrete. The monitored signal can reflect the viscoelastic-plastic deformation law of asphalt concrete. The sensor can be used to monitor the dynamic response of asphalt concrete.

scholarly journals Assembly of Carbon Dots into Frameworks with Enhanced Stability and Antibacterial Activity

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Pengfei Zhuang ◽  
Kuo Li ◽  
Daoyong Li ◽  
Haixia Qiao ◽  
Yifeng E ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Carbon Dots ◽  
Inhibitory Concentration ◽  
Hydrothermal Process ◽  
Active Surface ◽  
Practical Applications ◽  
E Coli ◽  
Antibacterial Performance ◽  
The Stability

AbstractCarbon dots (CDs) have been widely used as antimicrobials due to their active surface, but some CDs suffer instability. Therefore, the relative applications such as the antibacterial activity may not be reliable for long-term use. Herein, we synthesize CDs with blue fluorescence by a hydrothermal process. Thereafter, polyethylenimine was applied for the assembly of CDs into CDs-based frameworks (CDFs). The CDFs exhibited quenched fluorescence but showed more stable properties based on the scanning electron microscope and zeta potential investigations. Both CDs and CDFs show antibacterial activity toward Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), but CDFs exhibited better antibacterial performance, and S. aureus could be completely inhibited with the minimum inhibitory concentration of 30 μg/mL. This reveals CDFs magnify both the stability and antibacterial activity, which would be more promising for practical applications. Graphic abstract

Instability Threshold and Stability Boundaries of Rotor-Bearing Systems

1996 ◽  
Vol 118 (1) ◽  
pp. 115-121 ◽  
Author(s):  
W. J. Chen
Keyword(s):  
High Speed ◽  
Equations Of Motion ◽  
Optimization Techniques ◽  
Instability Threshold ◽  
System Stability ◽  
Stability Boundaries ◽  
Practical Applications ◽  
Design Variables ◽  
Rotor Bearing ◽  
The Stability

A direct numerical method for the determination of instability threshold and stability boundaries of flexible rotor-bearing systems is presented. The proposed procedure can also be used to improve the system stability by considering the design variables as operating parameters. The finite element method is utilized in the formulation of system equations of motion. The numerical algorithm is based on nonlinear optimization techniques. Two examples are presented to illustrate the feasibility, desirability, and ability of the proposed algorithm. A simple journal bearing system is used for the parametric study. An industrial high-speed compressor is employed to demonstrate the ability of this algorithm to deal with practical applications. The stability boundaries calculated from this algorithm are in agreement with the experimental results.

Investigation of Multiwavelength Optical Power Limiting Amplifier and its Applications in High-Speed Sonet Wavelength-Division Multiplexing Self-Healing Ring Network

1997 ◽  
Vol 08 (04) ◽  
pp. 767-777
Author(s):  
Yung-Kuang Chen ◽  
Shien-Kuei Liaw ◽  
Sien Chi
Keyword(s):  
Wavelength Division Multiplexing ◽  
High Speed ◽  
Dynamic Range ◽  
Noise Figure ◽  
Optical Power ◽  
Low Noise ◽  
Self Healing ◽  
Channel Output ◽  
Limiting Amplifier ◽  
Optical Power Limiting

A multiwavelength optical power limiting amplifier (OLA) for high-speed SONET self-healing ring (SHR) networks is reported. Four possible OLA configurations are investigated. We find that the configuration consisting of a high-gain common erbium-doped fiber amplifier (EDFA) followed by a grating-multiplexed multiple-power-EDFA module is the best scheme for multiwavelength power-limiting operation. A constant channel output of > 11 dBm, small inter-channel power variation of ≤ 0.5 dB, and fairly low noise figure are obtained within a large dynamic range of 45 dB. Network application in a SHR network is also demonstrated and the ring size of 150 km served by a single three-WDM-channel OLA at channel rates of 2.488 Gb/s is obtained.

scholarly journals Performance Investigation on Different Designs of Superhydrophobic Surface Texture for Composite Insulator

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1164 ◽  
Author(s):  
Meiyun Zhao ◽  
Wei Li ◽  
Yang Wu ◽  
Xinze Zhao ◽  
Mingyi Tan ◽  
...  
Keyword(s):  
Superhydrophobic Surface ◽  
High Speed ◽  
Three Dimensional ◽  
Optimal Parameters ◽  
Textured Surfaces ◽  
Composite Insulator ◽  
Camera System ◽  
Practical Applications ◽  
Column Design

To investigate the superhydrophobic properties of different surface textures, nine designs of textures with micro-nanostructures were produced successfully using the laser engraving technique on the surfaces of composite insulator umbrella skirt samples made of silicon rubber. The optimal parameters of the texture designs to give rise to the best hydrophobicity were determined. The surface morphology, abrasion resistance, corrosion resistance, self-cleaning and antifouling property of the different textured surfaces as well as water droplets rolling on the textured surfaces were studied experimentally using a contact angle meter, scanning electron microscope, three-dimensional topography meter and high-speed camera system. It was found that the diamond column design with optimal parameters has the best superhydrophobicity and overall performance. The most remarkable advantage of the optimal diamond column design is its robustness and long-term superhydrophobicity after repeated de-icing in harsh conditions. The reported work is an important step towards achieving superhydrophobic surface without coating for outdoor composite insulator in practical applications.

scholarly journals Computational optical sectioning with an incoherent multiscale scattering model for light-field microscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Zhang ◽  
Zhi Lu ◽  
Jiamin Wu ◽  
Xing Lin ◽  
Dong Jiang ◽  
...  
Keyword(s):  
High Speed ◽  
Light Field ◽  
Superior Performance ◽  
Optical Sectioning ◽  
Complete Space ◽  
Entire Volume ◽  
Scattering Model ◽  
Practical Applications ◽  
Living Organisms

AbstractQuantitative volumetric fluorescence imaging at high speed across a long term is vital to understand various cellular and subcellular behaviors in living organisms. Light-field microscopy provides a compact computational solution by imaging the entire volume in a tomographic way, while facing severe degradation in scattering tissue or densely-labelled samples. To address this problem, we propose an incoherent multiscale scattering model in a complete space for quantitative 3D reconstruction in complicated environments, which is called computational optical sectioning. Without the requirement of any hardware modifications, our method can be generally applied to different light-field schemes with reduction in background fluorescence, reconstruction artifacts, and computational costs, facilitating more practical applications of LFM in a broad community. We validate the superior performance by imaging various biological dynamics in Drosophila embryos, zebrafish larvae, and mice.

The Stability of the WHO Reference Thromboplastin NIBS & C 67/40

1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram
Keyword(s):  
Human Brain ◽  
Collaborative Study ◽  
Calibration Constant ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Show Evidence ◽  
Human Material ◽  
Reference Preparation ◽  
The Stability

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

Saskatchewan Highways and Transportation Reduced Tire Pressure Initiative

1997 ◽  
Vol 1589 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Thomas L. Davies ◽  
Tami F. Wall ◽  
Allan Carpentier
Keyword(s):  
High Speed ◽  
Membrane Surface ◽  
Vehicle Stability ◽  
Road Maintenance ◽  
Long Term Effects ◽  
Tire Pressure ◽  
Reduced Pressure ◽  
Maintenance Costs ◽  
Short And Long Term

After examination of the research carried out by other agencies, Saskatchewan Highways and Transportation (SHT) embarked on an initiative to adapt low tire pressure technologies to the province's needs and environment. The focus of the initiative was to explore several technical questions from SHT's perspective: (a) Can low tire pressures be used to increase truck weights from secondary to primary without increasing road maintenance costs on thin membrane surface roads? (b) What are the short- and long-term effects of tire heating under high-speed/high-deflection constant reduced pressure (CRP) operations in a Saskatchewan environment? (c) What effects do lower tire pressures have on vehicle stability at highway speeds? To date, significant opportunities have been noted on local hauls (less than 30 min loaded at highway speeds) for CRP operation and long primary highway hauls that begin or end in relatively short secondary highway sections that limit vehicle weight allowed for the whole trip for central tire inflation technology. The background and environment for the initiative and the investigations and demonstrations envisioned and undertaken are briefly outlined.

Sign in / Sign up

Export Citation Format

Share Document