Search results

Basing on the theory of power flow, frequency response analysis was acted on in a hydropower house under dominant frequency with measured data of Three Gorges Station in spiral case and draft tube.
And the application of the theory had achieved progress in more fields such as shipping vibration reduction and isolation, automobile manufacturer and noise control, and so on.
The conclusions were helpful for powerhouse vibration reduction, dangerous analysis and reinforcement projects in the further. 2.

The obtained data show influence of particle size and chemical composition of tested powders on their pozzolanic activity, which corresponds with the results of Frattini and modified Chapelle test.
In addition to that, the grain size of the cement matrix is enhanced due to the reduction of the content and size of calcium hydroxide crystals, which cause the developing of compact material matrix and the transition zone between matrix and the filler [4].
Direct methods monitor the presence of Ca(OH)2 and its subsequent reduction in abundance with time as the pozzolanic reaction proceeds, using analytical methods such as X-ray diffraction (XRD), thermo – gravimetric analysis (TGA) or classical chemical analysis [5].

It is challenging to get accurate data for the morphology and positions of air void phases of PAC.
Reconstruction The mutil-angel projection method is used to gathered the data from computed tomography scan and used the principle of image reconstruction to calculate the inside construction of the object. represents the point of the object in the function, and the Eq. 3 represents the actinism of the point that intercepts the function. t represents the distance from the original point to the actinism, and represents the included angle between the actinism and parallel line.
The gradation data was gathered and base on the gathered statistics, the prediction of the permeability of the mixture was possible.
The reduction of the void construction space or the amount of void will cause the performance of PAC to decrease drastically.
The reduction of the void construction space or the amount of void will cause the inability to perform proper function, and also the clogging of PAC.

The temperature-time data were recorded using a high-speed data acquisition system (EPAD-TH8-K) linked to a computer with DEWESoft 7.05 at a dynamic rate of 100 Hz/ch, as shown in Fig. 1.
FlexPro8.0.31 data analysis software was used for smoothing the curves and plotting the cooling curve and first derivative curve for extracting the characteristics data.Samples for metallography were cut and prepared by standard grinding and polishing procedure.
It is clearly perceived that 0.4wt.% Bi is the best concentration to be added to the composite in order to alter the morphology and obtained adequate refinement effect on the Mg2Si structure. 0.4wt.% Bi has resulted in the biggest reduction in size from 179.4 to 115.92 µm, about 35% reduction, similar to aspect ratio which also decreased from 1.2 to 1.08 by 10% and produced high density particles distribution, about 38 from 12 particles per unit area in mm2.

Fortunately, Kirsons' data [6] for different samples offer a possibility to estimate this doping-dependence of Sph at least for n-6H-SiC (see Fig.2).
Data correspond to the publications [3-5].
The µ meff -term explains also the close Sph values for p- and n-type materials (see Ge and Si data in Fig.1).
In the present preliminary study the doping dependent reductions of κ and Sph at doping levels close to the 1019 cm-3 as well as sample size dependent boundary scattering reductions at temperatures close and below 50K were omitted.
More experimental data and adequate material parameter models for wide temperature and doping density ranges are needed for a more detailed analysis of this problem.

This data illustrate the difficulties of the problem, weak progress in finding ways to resolve it and the need for further research.
Preliminary remarks The existing practice of exploiting ACS shows that improved accuracy settings with simulations time reduction of performance this operation an be achieved only if there is a hardware-software tools, making possible configure in the automatic or automated mode.
For algorithmic and instrument constructions it means calculations reduction, better performance, cost reduced of physical realizations, etc.
Pros adopted version: - The combination in one device controller and touch pad; - The ability to create software controller and visualization in a single software environment; - Expanded the number of interfaces; - The possibility of data transfer protocols MODBUS (RTU, ASCII, TCP), OWEN, CANopen; - The presence of a large amount of Flash- memory, with the possibility of extension; - Expandable inputs and outputs signals of various types.
Typically, this is due to a limitation in the number of supported data types, more simplified interpreted translator, intermediate code.

The sensors were connected to a multi-channelled data logger known as the Babuc A from LSI Italy and the data obtained were recorded.
The data obtained from the Babuc A data logger were then used to calculate the thermal conductivity of the material studied by using the general equation stated by Eq. 1.
There are various elements that can contribute to the reduction of thermal conductivity value including the type of materials used and the characteristics of the pore structures of the insulation material [12].
In the current study, inclusions of bast-typed kenaf fiber in sand-cement blocks were seen to influence the reduction of the thermal conductivity value.

By polarization curve researchers can get a lot of important parameters, such as tafel slope, corrosion current, cathodic reduction limiting current density and so on.
According to mixed potential theory, Li Cheng-bao [2]used intercept method for soil corrosion system which controlled by oxygen concentrated difference polarization.It calculated the instantaneous corrosion rate from steel electrode low polarization data of water saturated soil medium and first oxygen ionization reaction speed control or mixed control and then is oxygen diffusion control.
Using low polarization curve technique to deal with the polarization curve data become a new electrochemical method to study soil corrosion behavior.
Through the related software to make full use of the low polarization fitting data, it can accurately calculate relevant electrochemical parameters, and judge the corrosion control mechanism from the parameters.
Review in Experimentation and Data Processing of Soil Corrosion[J].Corrosion Science and Protection Technology,2003,15(3):154-160.

Risk assessment of the power system operation state to clear that the operation states of the power system have important significance for the guarantee of the power system safe operation and the reduction of disaster loss.
To solve the above problem, this paper considers the likelihood and severity of the power system fault based on risk theory, and builds a fault probability model by using the fault probability of the power system in severe weather based on statistical analysis of historical data and a severity index system of power system static security from 3 risks of branch overload, bus voltage violation and loss of load.
The computation formula of the fault probability of power system in severe weather can be expressed as follow: (5) Where is the fault probability of ith branch in severe weather, its value based on historical data.
We hypothesize that the annual broken rates of line 1, line 4 and line 6 breaking in severe weather based on historical data statistics were 0.5, 0.4 and 0.2 respectively.
It can provide theoretical support for the analysis of high-risk lines in severe weather and the reduction of disaster loss.

Goss et al [4] developed a risk-based index for source water protection planning, which supports the reduction of pathogens from agricultural activity entering water resources.
The horizontal coordinate data are obtained by converting the geographic coordinate system into Beijing 54 geodetic coordinates systems.
The flow data were obtained from the monitoring data.
The flow data in June, 2012 was selected as the model of inflow and outflow.
Development of a risk-based index for source water protection planning, which supports the reduction of pathogens from agricultural activity entering water resources: Journal of Environmental Management Vol. 87 (2008), p.623-632 [5]Y.Y.