Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can b...Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.展开更多
The dynamic monitoring of landslides in engineering geology has focused on the correlation among landslide stability,rainwater infiltration,and subsurface hydrogeology.However,the understanding of this complicated cor...The dynamic monitoring of landslides in engineering geology has focused on the correlation among landslide stability,rainwater infiltration,and subsurface hydrogeology.However,the understanding of this complicated correlation is still poor and inadequate.Thus,in this study,we investigated a typical landslide in southwestern China via time-lapse electrical resistivity tomography(TLERT) in November 2013 and August 2014.We studied landslide mechanisms based on the spatiotemporal characteristics of surface water infiltration and flow within the landslide body.Combined with borehole data,inverted resistivity models accurately defined the interface between Quaternary sediments and bedrock.Preferential flow pathways attributed to fracture zones and fissures were also delineated.In addition,we found that surface water permeates through these pathways into the slipping mass and drains away as fissure water in the fractured bedrock,probably causing the weakly weathered layer to gradually soften and erode,eventually leading to a landslide.Clearly,TLERT dynamic monitoring can provide precursory information of critical sliding and can be used in landslide stability analysis and prediction.展开更多
Crack monitoring plays a great role in modern structural health monitoring, however, most of the conventional crack inspections have disadvantages in terms of the accuracy, expense, reliability, durability and level o...Crack monitoring plays a great role in modern structural health monitoring, however, most of the conventional crack inspections have disadvantages in terms of the accuracy, expense, reliability, durability and level of instrumentation required. Thus, development of a simple and reliable crack inspection technique that allows continuous monitoring has been desired. In this paper, electrical potential technique and modern surface technology are employed together to develop a new structural surface crack monitoring method. A special crack monitoring coating sensor based on electrical potential technique was deposited on the hot spot of the structure by modern surface technology. The sensor consists of three layers: the isolated layer, the sensing layer and the protective layer. The isolated layer is prepared by anodic oxidation technology, the sensing layer is made of ion plated copper, and the protective layer is made of silicone. The thickness of each layer is at micrometer magnitude. The electrical conductivity of the sensor is very stable, and the fatigue performance of the specimen with or without coating sensor is nearly unchanged. The crack monitoring experiment result shows that there are two sudden rises of the coating sensor electrical potential values, corresponding to different stages of the crack initiation and propagation. Since the width of the surface coating sensor is only 0.5 mm, this crack monitoring sensor can detect the propagation of cracks less than 0.5 mm long. The method proposed takes the simplicity of electrical potential technique and can monitor surface crack of nearly all kinds of structures precisely. The results of this paper may form the basis of a new crack monitoring system.展开更多
This paper describes the shortcomings and difficulties of power company security construction, such as site management for construction site security monitoring personnel is limited, in recent years , rural power grid...This paper describes the shortcomings and difficulties of power company security construction, such as site management for construction site security monitoring personnel is limited, in recent years , rural power grids and Urban Network alteration Faced with new situation. The use of advanced science and technology and communication terminal in order to better strengthen the means of power construction site safety supervision, improve the level of safety production supervision, design and development of a new electrical safety job site intelligent monitoring devices. The device consists of three parts of the remote wide angle 360 degrees of portable video surveillance equipment and 3G smart terminal equipment and portable battery. Through the application of such a device, professionals can remotely monitor the construction job site safety, diagnose, and effectively improve the security of the electricity sector management and reduce security risks and personnel on-site monitoring costs for improving the security of the entire power industry field operations with significance.展开更多
In order to online monitor the running state of variable voltage and variable frequency(VVVF)hydraulic system,this paper presents a graphic monitoring method that fuses the information of variable frequency electric p...In order to online monitor the running state of variable voltage and variable frequency(VVVF)hydraulic system,this paper presents a graphic monitoring method that fuses the information of variable frequency electric parameters.This paper first analyzes how the voltage and current of the motor stator change with the operation conditions of VVVF hydraulic system.As a result,we draw the relationship between the electric parameters(voltage and current)and power frequency.Then,the signals of the voltage and current are fused as dynamic figures based on the idea of Lissajous figures,and the values of the electric parameters are related to the features of the dynamic figures.Rigorous theoretical analysis establishes the function between the electric power of the variable frequency motor(VFM)and the features of the plotted dynamic figures including area of diagram,area of bounding rectangle,tilt angle,etc.Finally,the effectiveness of the proposed method is verified by two cases,in which the speed of VFM and the load of VVVF hydraulic system are changed.The results show that the increase of the speed of VFM enhances its three-phase electric power,but reduces the tilt angle of the plotted dynamic figures.In addition,as the load of VVVF hydraulic system is increased,the three-phase electric power of VFM and the tilt angle of the plotted dynamic figures are both increased.This paper provides a new way to online monitor the running state of VVVF hydraulic system.展开更多
Objective: To compare the haemodynamic effects of the induction agents ketamine, etomidate and sevoflurane using the model of electrical velocimetry based cardiac output monitoring in paediatric cardiac surgical patie...Objective: To compare the haemodynamic effects of the induction agents ketamine, etomidate and sevoflurane using the model of electrical velocimetry based cardiac output monitoring in paediatric cardiac surgical patients. Design: Prospective randomized study. Setting: Tertiary care hospital. Participants: 60 children < 2 years age undergoing cardiac surgery. Interventions: The patients were randomized into 3 equal groups to receive 1.5-2.5 mg/kg iv ketamine (group K), 0.2-0.3 mg/kg iv etomidate (group E) or upto 8% sevoflurane (group S) as the induction agent. Hemodynamic parameters were noted before and after induction of anaesthesia utilizing a noninvasive cardiac monitor based on the model of electrical velocimetry. Measurements and Main Results: The demographic characteristics of the patients were similar in the three groups. The HR decreased in all groups, least in group E (P ≤ 0.01) but the MAP decreased only in group S (P ≤ 0.001). In group S, the stroke volume improved from 9 ± 3.2 ml to 10 ± 3.2 ml (P ≤ 0.05) and the stroke volume variation decreased from 25% ± 6.4% to 13% ± 6.2% (P ≤ 0.001). The stroke index and systemic arterial saturation improved in all groups (P ≤ 0.01). The cardiac index and index of contractility were unchanged. The transthoracic fluid content reduced in groups E and S, but did not change in group K (P ≤ 0.05). Conclusions: Etomidate appeared to provide the most stable conditions for induction of anesthesia in children undergoing cardiac surgery, followed by ketamine and sevoflurane.展开更多
To protect mining areas from electrical fire, it is very important to install electrical nre momtormg system to ensure safety in development of mineral resources and for buildings. In this paper, design for electrical...To protect mining areas from electrical fire, it is very important to install electrical nre momtormg system to ensure safety in development of mineral resources and for buildings. In this paper, design for electrical fire monitoring and detection system with optional sensor modules has been proposed. In addition, necessity and suitability of electrical fire monitoring and detection system with optional sensor modules in mining areas have been reviewed. The designed electrical fire monitoring and detection system suit- able for work environment of mining industry is composed by host-computer monitoring software and slave-computer detectors. Monitoring detectors are manufactured by using embedded technology. Exter- nal shells deployed have superior enclosure performances and explosion-proof properties. It is easy to install and maintain the system. In general, the system has reached, or even exceeded standards specified in national standards for performances and appearances of such devices. Test results show application of electrical fire monitoring and detection system can effectively enhance monitoring intensity over the mining areas and provide reliable guarantee to ensure orderly development of mineral resources and to protect physical and property safety of citizens in these areas.展开更多
A new novel function materials, structure self-monitoring asphalt-based composite was introduced. The results show that the output resistance of electrically conductive asphalt-based composites would change under cycl...A new novel function materials, structure self-monitoring asphalt-based composite was introduced. The results show that the output resistance of electrically conductive asphalt-based composites would change under cyclic loading and vehicle loading action. The resistance change of conductive asphalt-based composites was aroused by the variation of its interior structure. When the fatigue failure was studied, the larger cracks cut the continuous electrically conductive path and the electron is difficult to overcome the potential barrier of gap. In the early period, the slight deformation and microcrack may be recovered due to the viscoelasticity character of asphalt, which leads to some cracks close again, the output resistance changes a little. But with the shear process performs continuously, the cracks become larger and larger, which would cut the conductive path and block off the transition of electrons, and if the cracks are large enough, the pitch-matrix composites containing carbon fillers will lose electrically conductive function. When the rutting failure was studied, the flowage of conductive substance results in the decrease of substance due to electrically conducting and conductive path decreasing. The decrease of electron volume contribute to electrically conducting and large stone aggregate prevent the electron from transiting. In a word, the variation of output resistance is aroused by the variation of interior structure completely.展开更多
This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in t...This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.展开更多
The piezoelectric effect is used in sensing applications such as in force and displacement sensors.However,the brittleness and low performance of piezoceramic lead zirconate titanate(PZT) often impede its applicabilit...The piezoelectric effect is used in sensing applications such as in force and displacement sensors.However,the brittleness and low performance of piezoceramic lead zirconate titanate(PZT) often impede its applicability in civil structures which are subjected to large loads.The concept of a piezocomposite electricity generating element(PCGE) has been proposed for improving the electricity generation performance and overcoming the brittleness of piezoceramic wafers.The post-curing residual stress in the PZT layer constitutes a main reason for the PCGE's enhanced performance,and the outer epoxy-based composites protect the brittle PZT layer.A d33-mode PCGE designed for bridge monitoring application was inserted in a bridge bearing to provide a permanent and simple weigh-in-motion system.The designed PCGEs were tested through a series of tests including fatigue and dynamic tests to verify their applicability for monitoring purposes in a bridge structure.A simple beam example was presented to show the applicability of the proposed bridge bearing equipped with the PCGE for adequately measuring the traffic loads.展开更多
A part of the Earth's surface has been formed by the action of running water during geomorphological development. The flow of water is one of the ways of how particles can be eroded, transported and accumulated. If e...A part of the Earth's surface has been formed by the action of running water during geomorphological development. The flow of water is one of the ways of how particles can be eroded, transported and accumulated. If endogenous processes do not work, the surface of the continents would lower to the level close to the ocean surface and the relief would have almost no ruggedness. Recently, there have been talks about the relative classification of deviation of the present state from the "original" or "natural" one caused by anthropogeneous effects. The activity of man can manifest itself by pollution, the excessive use of water, a change in the flow regime, and the like. Research into the morphology of the river bottom and the bottom of settling tanks or dam reservoirs is systematically carried out in selected streams and reservoirs by the long-term sampling of bottom sediments. The knowledge of the sediment layer is also important. The EIS method, which was used for measuring, is new for the aforementioned applications. Possibilities of EIS method with new apparatus using for this application were tested in laboratory and in situ. On the basis of interpretation of the electrical conductivity data, a grid of depth data was acquired. These data are characterized by anomalously high and low "spots" and show morphological changes in the studied area.展开更多
With the continuous improvement of industrial automation in our country and the use of high technology, promoted the scientific content of traditional industry. The development of electric automation control system in...With the continuous improvement of industrial automation in our country and the use of high technology, promoted the scientific content of traditional industry. The development of electric automation control system inevitably turn towards a systematic, comprehensive development direction. This article first analyze the present problems in electrical automation monitoring system, analyzes its future development trends, so as to provide some reference for the effective application of electrical automation in the future monitoring system, fundamentally realize the resources sharing.展开更多
Nuclear power plants (NPPs) are considered as the main source for generating electricity nowadays in some countries. The effect of impact of heavy fully loaded aeroplane such as (Boeing 747-200c) causes leakage of the...Nuclear power plants (NPPs) are considered as the main source for generating electricity nowadays in some countries. The effect of impact of heavy fully loaded aeroplane such as (Boeing 747-200c) causes leakage of the radiation through the cracks generated on the external RC containment of NPPs, and this leads to severe damage for humans and cities. In this research paper, external RC containment </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">is</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> modeled using ANSYS and hit by Boeing 747-200c which is the heavier aeroplane compared to other jets and causes severe damage for external RC containment. In addition, the impact location for Boeing 747-200c is considered at 30</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">m vertical height. RC containment response was studied after the impact of an aeroplane and a proposed structural health monitoring technique is applied using embedded sensors in order to detect and locate the embedded cracks that is generated due to the effect of impact of heavy aeroplane. It was concluded that RC containment is intact except for the impact region which is damaged. An experimental program was applied on a part of the element in ANSYS which is away from the impact region. Four specimens were cast using heavy weight concrete in laboratory. Three cracked specimens consist of different lengths of vertical cracks which represent different times of impact in order to replicate crack propagation as in ANSYS. The cracks are simulated inside laboratory specimens using failure criteria. The parameters used in detecting the cracks for specimens are the percentage change in electrical resistivity and Decimal Logarithm Resistivity Anisotropy (DLRA) at which they give a good indication for the presence of the crack.展开更多
In order to improve the management and control requirements of small electric kilns in ceramic production field.According to the excessive dispersion of electric kilns in porcelain production field,a remote monitoring...In order to improve the management and control requirements of small electric kilns in ceramic production field.According to the excessive dispersion of electric kilns in porcelain production field,a remote monitoring system based on RS485 bus and Modbus protocol is designed.The system consists of data acquisition,field control,cloud monitoring and communication protocol.MCGS is used as the master station to communicate with the temperature controller,collect and transmit the internal data to Siemens PLC.Through the communication between Siemens PLC and IOT gateway,the kiln working data is uploaded to the cloud platform to realize the remote monitoring for ceramic electric kiln.The experimental results showed this system can accurately collect the working temperature and parameters of the kiln in real time,and can remotely cortrol the kiln.展开更多
The electrical transmission networks are complex systems that are commonly run near their operational limits. Such systems can undergo major disturbances that have serious consequences. Individually, these disturbance...The electrical transmission networks are complex systems that are commonly run near their operational limits. Such systems can undergo major disturbances that have serious consequences. Individually, these disturbances can be attributed to specific causes, such as lightning strikes, ice storms, equipment failure, shorts resulting from untrimmed trees, excessive customer demand, or human errors. In the paper, the human errors from electrical transmission networks of Romanian Power Grid Company over period of 10 years are analyzed. It is hoped that obtained results will provide engineers a better understanding so they can cater to the needs of the human operators when to implement new interfaces for network monitoring tasks, not for the other technical objectives.展开更多
Nowadays,the advancement of nonintrusive load monitoring(NILM)has been hastened by the ever-increasing requirements for the reasonable use of electricity by users and demand side management.Although existing researche...Nowadays,the advancement of nonintrusive load monitoring(NILM)has been hastened by the ever-increasing requirements for the reasonable use of electricity by users and demand side management.Although existing researches have tried their best to extract a wide variety of load features based on transient or steady state of electrical appliances,it is still very difficult for their algorithm to model the load decomposition problem of different electrical appliance types in a targeted manner to jointly mine their proposed features.This paper presents a very effective event-driven NILM solution,which aims to separately model different appliance types to mine the unique characteristics of appliances from multi-dimensional features,so that all electrical appliances can achieve the best classification performance.First,we convert the multi-classification problem into a serial multiple binary classification problem through a pre-sort model to simplify the original problem.Then,ConTrastive Loss K-Nearest Neighbour(CTLKNN)model with trainable weights is proposed to targeted mine appliance load characteristics.The simulation results show the effectiveness and stability of the proposed algorithm.Compared with existing algorithms,the proposed algorithm has improved the identification performance of all electrical appliance types.展开更多
This article introduces the 40 kW electric servo system used by Gravity-1 strap-on launch vehicle, which mainly includes the composition, function and related equipment of the system. Aiming at the measurement deviati...This article introduces the 40 kW electric servo system used by Gravity-1 strap-on launch vehicle, which mainly includes the composition, function and related equipment of the system. Aiming at the measurement deviation caused by the closed loop of resolver, a compensation algorithm is designed;aiming at the monitoring of the output power of the thermal battery, an algorithm without sensory monitoring the bus current is designed. In the end, the effectiveness of the two algorithms was verified by testing.展开更多
Αcloud-based home electricity data-monitoring system,which is based on an Arduino Mega controller,is proposed for monitoring the electricity consumption(electrical power)and power quality(PQ)in home.This system is al...Αcloud-based home electricity data-monitoring system,which is based on an Arduino Mega controller,is proposed for monitoring the electricity consumption(electrical power)and power quality(PQ)in home.This system is also capable of monitoring the fundamental frequency and supply-voltage transients to ensure that the appliances operate in a safe operation range.The measured data(voltage and current)are transmitted through a Wi Fi device between the Arduino controller and server.The transmission control protocol(TCP)server is set up to acquire the high-data transmission rate.The server system immediately displays the calculated parameters and the waveform of the acquired signal.A comparison with a standard measurement device shows that the proposed system,which can be built at a low cost,exhibits the same functions as a factory product.展开更多
The level of deformation development of surrounding rocks is a vital predictor to evaluate impending coal mine disasters and it is important to establish accurate measurements of the deformed status to ensure coal min...The level of deformation development of surrounding rocks is a vital predictor to evaluate impending coal mine disasters and it is important to establish accurate measurements of the deformed status to ensure coal mine safety. Traditional deformation monitoring methods are mostly based on single parameter, in this paper, multiple approaches are integrated: firstly, both electric and elastic models are established,from which electric field distribution and seismic wave recording are calculated and finally, the resistivity profiles and source position information are determined using inversion methods, from which then the deformation and failure of mine floor are evaluated. According to the inversion results of both electric and seismic field signals, multiple-parameter dynamic monitoring of surrounding rock deformation in deep mine can be performed. The methodology is validated using numerical simulation results which shows that the multi-parameter dynamic monitoring methods have better results for surrounding rock deformation in deep mine monitoring than single parameter methods.展开更多
A convenient approach was proposed by which to evaluate and monitor the permeability of a rock fracture by verifying the quantitative correlation between the electrical resistivity and permeability at laboratory scale...A convenient approach was proposed by which to evaluate and monitor the permeability of a rock fracture by verifying the quantitative correlation between the electrical resistivity and permeability at laboratory scale.For this purpose,an electrical resistivity measurement system was applied to the laboratory experiments using artificial cells with the shape of a single rock fracture.Sixty experiments were conducted using rock fractures according to the geometry,aperture sizes,wavelengths,and roughness amplitudes.The overall negative relationship between the normalized electrical resistivity values and the aperture sizes directly linked with the permeability,was well fitted by the power-law function with a large determination coefficient(≈0.86).The effects of wavelength and roughness amplitude of the rock fracture on the electrical resistivity were also analyzed.Results showed that the electrical resistivity was slightly increased with decreasing wavelength and increasing roughness amplitude.An empirical model for evaluating the permeability of a rock fracture was proposed based on the experimental data.In the field,if the electrical resistivity of pore groundwater could be measured in advance,this empirical model could be applied effectively for simple,quick monitoring of the fracture permeability.Although uncertainty may be associated with the permeability estimation due to the limited control parameters considered in this research,this electrical resistivity approach could be helpful to monitor the rock permeability in deep underground facilities such as those used for radioactive waste repositories or forms of energy storage.展开更多
基金the Natural Science Foundation of Beijing Municipality(2222075)National Natural Science Foundation of China(22279010,21671020,51673026)Analysis&Testing Center,Beijing Institute of Technology.
文摘Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.
基金funded by the National Basic Research Program of China(973 Program)(No.2013CB733203)the National Natural Science Foundation of China(No.41474055)
文摘The dynamic monitoring of landslides in engineering geology has focused on the correlation among landslide stability,rainwater infiltration,and subsurface hydrogeology.However,the understanding of this complicated correlation is still poor and inadequate.Thus,in this study,we investigated a typical landslide in southwestern China via time-lapse electrical resistivity tomography(TLERT) in November 2013 and August 2014.We studied landslide mechanisms based on the spatiotemporal characteristics of surface water infiltration and flow within the landslide body.Combined with borehole data,inverted resistivity models accurately defined the interface between Quaternary sediments and bedrock.Preferential flow pathways attributed to fracture zones and fissures were also delineated.In addition,we found that surface water permeates through these pathways into the slipping mass and drains away as fissure water in the fractured bedrock,probably causing the weakly weathered layer to gradually soften and erode,eventually leading to a landslide.Clearly,TLERT dynamic monitoring can provide precursory information of critical sliding and can be used in landslide stability analysis and prediction.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2009AA03Z103)Scientific Research Foundation for the Returned Overseas Chinese Scholars of Ministry of Education of China (Grant No. [2006]331)
文摘Crack monitoring plays a great role in modern structural health monitoring, however, most of the conventional crack inspections have disadvantages in terms of the accuracy, expense, reliability, durability and level of instrumentation required. Thus, development of a simple and reliable crack inspection technique that allows continuous monitoring has been desired. In this paper, electrical potential technique and modern surface technology are employed together to develop a new structural surface crack monitoring method. A special crack monitoring coating sensor based on electrical potential technique was deposited on the hot spot of the structure by modern surface technology. The sensor consists of three layers: the isolated layer, the sensing layer and the protective layer. The isolated layer is prepared by anodic oxidation technology, the sensing layer is made of ion plated copper, and the protective layer is made of silicone. The thickness of each layer is at micrometer magnitude. The electrical conductivity of the sensor is very stable, and the fatigue performance of the specimen with or without coating sensor is nearly unchanged. The crack monitoring experiment result shows that there are two sudden rises of the coating sensor electrical potential values, corresponding to different stages of the crack initiation and propagation. Since the width of the surface coating sensor is only 0.5 mm, this crack monitoring sensor can detect the propagation of cracks less than 0.5 mm long. The method proposed takes the simplicity of electrical potential technique and can monitor surface crack of nearly all kinds of structures precisely. The results of this paper may form the basis of a new crack monitoring system.
文摘This paper describes the shortcomings and difficulties of power company security construction, such as site management for construction site security monitoring personnel is limited, in recent years , rural power grids and Urban Network alteration Faced with new situation. The use of advanced science and technology and communication terminal in order to better strengthen the means of power construction site safety supervision, improve the level of safety production supervision, design and development of a new electrical safety job site intelligent monitoring devices. The device consists of three parts of the remote wide angle 360 degrees of portable video surveillance equipment and 3G smart terminal equipment and portable battery. Through the application of such a device, professionals can remotely monitor the construction job site safety, diagnose, and effectively improve the security of the electricity sector management and reduce security risks and personnel on-site monitoring costs for improving the security of the entire power industry field operations with significance.
基金National Natural Science Foundation of China(No.51675399)
文摘In order to online monitor the running state of variable voltage and variable frequency(VVVF)hydraulic system,this paper presents a graphic monitoring method that fuses the information of variable frequency electric parameters.This paper first analyzes how the voltage and current of the motor stator change with the operation conditions of VVVF hydraulic system.As a result,we draw the relationship between the electric parameters(voltage and current)and power frequency.Then,the signals of the voltage and current are fused as dynamic figures based on the idea of Lissajous figures,and the values of the electric parameters are related to the features of the dynamic figures.Rigorous theoretical analysis establishes the function between the electric power of the variable frequency motor(VFM)and the features of the plotted dynamic figures including area of diagram,area of bounding rectangle,tilt angle,etc.Finally,the effectiveness of the proposed method is verified by two cases,in which the speed of VFM and the load of VVVF hydraulic system are changed.The results show that the increase of the speed of VFM enhances its three-phase electric power,but reduces the tilt angle of the plotted dynamic figures.In addition,as the load of VVVF hydraulic system is increased,the three-phase electric power of VFM and the tilt angle of the plotted dynamic figures are both increased.This paper provides a new way to online monitor the running state of VVVF hydraulic system.
文摘Objective: To compare the haemodynamic effects of the induction agents ketamine, etomidate and sevoflurane using the model of electrical velocimetry based cardiac output monitoring in paediatric cardiac surgical patients. Design: Prospective randomized study. Setting: Tertiary care hospital. Participants: 60 children < 2 years age undergoing cardiac surgery. Interventions: The patients were randomized into 3 equal groups to receive 1.5-2.5 mg/kg iv ketamine (group K), 0.2-0.3 mg/kg iv etomidate (group E) or upto 8% sevoflurane (group S) as the induction agent. Hemodynamic parameters were noted before and after induction of anaesthesia utilizing a noninvasive cardiac monitor based on the model of electrical velocimetry. Measurements and Main Results: The demographic characteristics of the patients were similar in the three groups. The HR decreased in all groups, least in group E (P ≤ 0.01) but the MAP decreased only in group S (P ≤ 0.001). In group S, the stroke volume improved from 9 ± 3.2 ml to 10 ± 3.2 ml (P ≤ 0.05) and the stroke volume variation decreased from 25% ± 6.4% to 13% ± 6.2% (P ≤ 0.001). The stroke index and systemic arterial saturation improved in all groups (P ≤ 0.01). The cardiac index and index of contractility were unchanged. The transthoracic fluid content reduced in groups E and S, but did not change in group K (P ≤ 0.05). Conclusions: Etomidate appeared to provide the most stable conditions for induction of anesthesia in children undergoing cardiac surgery, followed by ketamine and sevoflurane.
基金the Science & Technology Research and Development Project of Langfang Municipal City for the Year 2013 (No.2013011048)Baoding GEEHO Electric Technology Development Co.,Ltd.for financial support and help in data acquisition and statistics during preparation of this paper
文摘To protect mining areas from electrical fire, it is very important to install electrical nre momtormg system to ensure safety in development of mineral resources and for buildings. In this paper, design for electrical fire monitoring and detection system with optional sensor modules has been proposed. In addition, necessity and suitability of electrical fire monitoring and detection system with optional sensor modules in mining areas have been reviewed. The designed electrical fire monitoring and detection system suit- able for work environment of mining industry is composed by host-computer monitoring software and slave-computer detectors. Monitoring detectors are manufactured by using embedded technology. Exter- nal shells deployed have superior enclosure performances and explosion-proof properties. It is easy to install and maintain the system. In general, the system has reached, or even exceeded standards specified in national standards for performances and appearances of such devices. Test results show application of electrical fire monitoring and detection system can effectively enhance monitoring intensity over the mining areas and provide reliable guarantee to ensure orderly development of mineral resources and to protect physical and property safety of citizens in these areas.
基金Project (2004ABB019) supported by the Outstanding Youth Foundation of Hubei Province, China project (NCET-05-0656) supported by the New Century Excellent Talents in Wuhan University
文摘A new novel function materials, structure self-monitoring asphalt-based composite was introduced. The results show that the output resistance of electrically conductive asphalt-based composites would change under cyclic loading and vehicle loading action. The resistance change of conductive asphalt-based composites was aroused by the variation of its interior structure. When the fatigue failure was studied, the larger cracks cut the continuous electrically conductive path and the electron is difficult to overcome the potential barrier of gap. In the early period, the slight deformation and microcrack may be recovered due to the viscoelasticity character of asphalt, which leads to some cracks close again, the output resistance changes a little. But with the shear process performs continuously, the cracks become larger and larger, which would cut the conductive path and block off the transition of electrons, and if the cracks are large enough, the pitch-matrix composites containing carbon fillers will lose electrically conductive function. When the rutting failure was studied, the flowage of conductive substance results in the decrease of substance due to electrically conducting and conductive path decreasing. The decrease of electron volume contribute to electrically conducting and large stone aggregate prevent the electron from transiting. In a word, the variation of output resistance is aroused by the variation of interior structure completely.
文摘This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.
基金Project supported by Konkuk University,Korea,in 2014
文摘The piezoelectric effect is used in sensing applications such as in force and displacement sensors.However,the brittleness and low performance of piezoceramic lead zirconate titanate(PZT) often impede its applicability in civil structures which are subjected to large loads.The concept of a piezocomposite electricity generating element(PCGE) has been proposed for improving the electricity generation performance and overcoming the brittleness of piezoceramic wafers.The post-curing residual stress in the PZT layer constitutes a main reason for the PCGE's enhanced performance,and the outer epoxy-based composites protect the brittle PZT layer.A d33-mode PCGE designed for bridge monitoring application was inserted in a bridge bearing to provide a permanent and simple weigh-in-motion system.The designed PCGEs were tested through a series of tests including fatigue and dynamic tests to verify their applicability for monitoring purposes in a bridge structure.A simple beam example was presented to show the applicability of the proposed bridge bearing equipped with the PCGE for adequately measuring the traffic loads.
文摘A part of the Earth's surface has been formed by the action of running water during geomorphological development. The flow of water is one of the ways of how particles can be eroded, transported and accumulated. If endogenous processes do not work, the surface of the continents would lower to the level close to the ocean surface and the relief would have almost no ruggedness. Recently, there have been talks about the relative classification of deviation of the present state from the "original" or "natural" one caused by anthropogeneous effects. The activity of man can manifest itself by pollution, the excessive use of water, a change in the flow regime, and the like. Research into the morphology of the river bottom and the bottom of settling tanks or dam reservoirs is systematically carried out in selected streams and reservoirs by the long-term sampling of bottom sediments. The knowledge of the sediment layer is also important. The EIS method, which was used for measuring, is new for the aforementioned applications. Possibilities of EIS method with new apparatus using for this application were tested in laboratory and in situ. On the basis of interpretation of the electrical conductivity data, a grid of depth data was acquired. These data are characterized by anomalously high and low "spots" and show morphological changes in the studied area.
文摘With the continuous improvement of industrial automation in our country and the use of high technology, promoted the scientific content of traditional industry. The development of electric automation control system inevitably turn towards a systematic, comprehensive development direction. This article first analyze the present problems in electrical automation monitoring system, analyzes its future development trends, so as to provide some reference for the effective application of electrical automation in the future monitoring system, fundamentally realize the resources sharing.
文摘Nuclear power plants (NPPs) are considered as the main source for generating electricity nowadays in some countries. The effect of impact of heavy fully loaded aeroplane such as (Boeing 747-200c) causes leakage of the radiation through the cracks generated on the external RC containment of NPPs, and this leads to severe damage for humans and cities. In this research paper, external RC containment </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">is</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> modeled using ANSYS and hit by Boeing 747-200c which is the heavier aeroplane compared to other jets and causes severe damage for external RC containment. In addition, the impact location for Boeing 747-200c is considered at 30</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">m vertical height. RC containment response was studied after the impact of an aeroplane and a proposed structural health monitoring technique is applied using embedded sensors in order to detect and locate the embedded cracks that is generated due to the effect of impact of heavy aeroplane. It was concluded that RC containment is intact except for the impact region which is damaged. An experimental program was applied on a part of the element in ANSYS which is away from the impact region. Four specimens were cast using heavy weight concrete in laboratory. Three cracked specimens consist of different lengths of vertical cracks which represent different times of impact in order to replicate crack propagation as in ANSYS. The cracks are simulated inside laboratory specimens using failure criteria. The parameters used in detecting the cracks for specimens are the percentage change in electrical resistivity and Decimal Logarithm Resistivity Anisotropy (DLRA) at which they give a good indication for the presence of the crack.
基金This paper was supported by Jiangxi Province Key Research and Development Program(202003BBG73071)。
文摘In order to improve the management and control requirements of small electric kilns in ceramic production field.According to the excessive dispersion of electric kilns in porcelain production field,a remote monitoring system based on RS485 bus and Modbus protocol is designed.The system consists of data acquisition,field control,cloud monitoring and communication protocol.MCGS is used as the master station to communicate with the temperature controller,collect and transmit the internal data to Siemens PLC.Through the communication between Siemens PLC and IOT gateway,the kiln working data is uploaded to the cloud platform to realize the remote monitoring for ceramic electric kiln.The experimental results showed this system can accurately collect the working temperature and parameters of the kiln in real time,and can remotely cortrol the kiln.
文摘The electrical transmission networks are complex systems that are commonly run near their operational limits. Such systems can undergo major disturbances that have serious consequences. Individually, these disturbances can be attributed to specific causes, such as lightning strikes, ice storms, equipment failure, shorts resulting from untrimmed trees, excessive customer demand, or human errors. In the paper, the human errors from electrical transmission networks of Romanian Power Grid Company over period of 10 years are analyzed. It is hoped that obtained results will provide engineers a better understanding so they can cater to the needs of the human operators when to implement new interfaces for network monitoring tasks, not for the other technical objectives.
基金supported by National Natural Science Foundation of China(No.61531007).
文摘Nowadays,the advancement of nonintrusive load monitoring(NILM)has been hastened by the ever-increasing requirements for the reasonable use of electricity by users and demand side management.Although existing researches have tried their best to extract a wide variety of load features based on transient or steady state of electrical appliances,it is still very difficult for their algorithm to model the load decomposition problem of different electrical appliance types in a targeted manner to jointly mine their proposed features.This paper presents a very effective event-driven NILM solution,which aims to separately model different appliance types to mine the unique characteristics of appliances from multi-dimensional features,so that all electrical appliances can achieve the best classification performance.First,we convert the multi-classification problem into a serial multiple binary classification problem through a pre-sort model to simplify the original problem.Then,ConTrastive Loss K-Nearest Neighbour(CTLKNN)model with trainable weights is proposed to targeted mine appliance load characteristics.The simulation results show the effectiveness and stability of the proposed algorithm.Compared with existing algorithms,the proposed algorithm has improved the identification performance of all electrical appliance types.
文摘This article introduces the 40 kW electric servo system used by Gravity-1 strap-on launch vehicle, which mainly includes the composition, function and related equipment of the system. Aiming at the measurement deviation caused by the closed loop of resolver, a compensation algorithm is designed;aiming at the monitoring of the output power of the thermal battery, an algorithm without sensory monitoring the bus current is designed. In the end, the effectiveness of the two algorithms was verified by testing.
基金supported by MOST under Grant No.106-2221-E-468-011-MY2。
文摘Αcloud-based home electricity data-monitoring system,which is based on an Arduino Mega controller,is proposed for monitoring the electricity consumption(electrical power)and power quality(PQ)in home.This system is also capable of monitoring the fundamental frequency and supply-voltage transients to ensure that the appliances operate in a safe operation range.The measured data(voltage and current)are transmitted through a Wi Fi device between the Arduino controller and server.The transmission control protocol(TCP)server is set up to acquire the high-data transmission rate.The server system immediately displays the calculated parameters and the waveform of the acquired signal.A comparison with a standard measurement device shows that the proposed system,which can be built at a low cost,exhibits the same functions as a factory product.
基金financial support from the Fundamental Research Funds for the Central Universities of China (No. 2015QNB19)the financial support from the Open Fund of Key Laboratory of Safety and High-efficiency Coal Mining, Ministry of Education of China (No. JYBSYS2015107)+2 种基金the National Natural Science Foundation of China (Nos. 51404254, 41430317 and U1261202)the China Postdoctoral Science Foundation of China (No. 2014M560465)the Jiangsu Planned Projects for Postdoctoral Research Funds of China (No. 1302050B)
文摘The level of deformation development of surrounding rocks is a vital predictor to evaluate impending coal mine disasters and it is important to establish accurate measurements of the deformed status to ensure coal mine safety. Traditional deformation monitoring methods are mostly based on single parameter, in this paper, multiple approaches are integrated: firstly, both electric and elastic models are established,from which electric field distribution and seismic wave recording are calculated and finally, the resistivity profiles and source position information are determined using inversion methods, from which then the deformation and failure of mine floor are evaluated. According to the inversion results of both electric and seismic field signals, multiple-parameter dynamic monitoring of surrounding rock deformation in deep mine can be performed. The methodology is validated using numerical simulation results which shows that the multi-parameter dynamic monitoring methods have better results for surrounding rock deformation in deep mine monitoring than single parameter methods.
基金supported by the National Research Foundation of Korea(KRF)grant funded by the Korea government(MSIT)(No.NRF-2019R1G1A1100517)the Basic Research and Development Project of the Korea Institute of Geoscience and Mineral Resources(KIGAM),which was funded by the Ministry of Science and ICT,Korea。
文摘A convenient approach was proposed by which to evaluate and monitor the permeability of a rock fracture by verifying the quantitative correlation between the electrical resistivity and permeability at laboratory scale.For this purpose,an electrical resistivity measurement system was applied to the laboratory experiments using artificial cells with the shape of a single rock fracture.Sixty experiments were conducted using rock fractures according to the geometry,aperture sizes,wavelengths,and roughness amplitudes.The overall negative relationship between the normalized electrical resistivity values and the aperture sizes directly linked with the permeability,was well fitted by the power-law function with a large determination coefficient(≈0.86).The effects of wavelength and roughness amplitude of the rock fracture on the electrical resistivity were also analyzed.Results showed that the electrical resistivity was slightly increased with decreasing wavelength and increasing roughness amplitude.An empirical model for evaluating the permeability of a rock fracture was proposed based on the experimental data.In the field,if the electrical resistivity of pore groundwater could be measured in advance,this empirical model could be applied effectively for simple,quick monitoring of the fracture permeability.Although uncertainty may be associated with the permeability estimation due to the limited control parameters considered in this research,this electrical resistivity approach could be helpful to monitor the rock permeability in deep underground facilities such as those used for radioactive waste repositories or forms of energy storage.