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Online since: October 2014
Authors: Gheorghe Mustea, Bogdan Chirita, Gheorghe Brabie
This process is applied after different machining operations in a single hybrid process and can lead to the following advantages: the improvement of the part surfaces quality and to an important reduction of the costs and manufacturing times.
The burnishing-cutting process also leads to an important reduction of the costs and manufacturing times [1, 4].
The conclusions resulted from the data analysis are as follows: · the mathematical model that defines the surface roughness is robust and significant; · the surface roughness can be improved by feed rate reduction and pressing pressure increasing, situation that is similar to that obtained from experimental results.
Herdness (HB) variation as a function of different working parameters The conclusions resulted from the data analysis are as follows: · the mathematical model that defines the surface hardness is robust and significant; · surface hardness increases with the increase of pressing pressure, part rotation speed and cutting depth and decreases with the increase of feed rate.
Values of the surface roughness and hardness obtained from experiment v s ap P Roughness Hardness [m/min] [mm/rot] [mm] [bar] [µm] [HB] 150.39 0.10 0.75 150.00 0.122 179.533 The conclusions resulted from the data analysis are as follows: · the roughness and hardness values of the surfaces obtained from experimental tests are approximately equal to that obtained from application of the Response Surfaces method; · the determination of the optimal values of working parameters ensures a better understanding on the surface quality resulted from the application of the cutting-burnishing process.
Online since: December 2011
Authors: T. Leffers, Feng Xiang Lin, W. Pantleon, Dorte Juul Jensen
Higher rolling reduction led to a stronger cube texture.
This material was cold rolled to 90% and 95% reduction in thickness.
Pole figures as presented in Fig. 1 were calculated from the orientation data.
In the 90% reduction sample the volume fraction of the cube component was 5.6% after recrystallization, while in the 95% reduction sample it increased to 14.1%.
a) maximum density: 2.5 b) maximum density: 5.7 c) maximum density: 5.3 d) maximum density: 2.6 e) maximum density: 23.6 f) maximum density: 5.1 Fig.1 {111} Pole figures of different recrystallized samples: a) sample 1; 90% reduction, b) sample 1; 95% reduction, c) sample 2; 95% reduction, d) sample 3; 90% reduction, e) sample 4; 90% reduction, f) sample 5; 90% reduction.
Online since: December 2013
Authors: You Hong Xiao, Xin Na Tian, Wei Zheng, Yu Shan Jin
Based on Eley-rideal mechanism,four major chemical reactions including the adsorption of ammonia, desorption of ammonia, selective catalytic reduction and oxidation of adsorbed ammonia are selected to study the SCR control strategy.
Combinedwith the equations of chemical reaction process,a mathematical model of SCR catalytic converteris established.To achieve a high NOX reduction efficiencyof SCR system, thereasonable and efficacious control strategies for the micro-element models of SCR catalytic is simulated,which including the feedback control strategy based on the feed-forward controller and the PID control strategy.
The problem how to constitute a reasonable control strategyis the main challenge of the SCR system, which is to achieve high NOX reduction which is over 80% and low ammonia slip that is less than 25ppm.
Table-1Simulation Data and Results The ratio of ammonia and nitrogen NOX,in=1000ppm NOX,in=1500ppm NOX,in=2000ppm Conversion rate (%) Conversion rate (%) Conversion rate (%) 0.45 82.97 84.85 85.29 0.75 83.07 84.45 85.39 1.05 83.01 84.65 85.39 The feedback and feed-forwardcontrol strategy.The ratio of CNOx,IIand CNH3,IIwasset to a fixed value as the feed-forward controller.
Table-2 Simulation Data and Results Amplification factor Nitrogen Oxide emissions 1000ppm NOx,out NH3,out mol/s ppm mol/s ppm 10 1.03e-3 203.43 1.01e-4 10.73 100 9.92e-4 195.92 1.07e-4 11.37 1000 7.42e-4 146.55 1.62e-4 17.21 Compared to the traditional SCR control strategy, this model can improve the control performance of SCR system with the dramatic changes of conditions in a certain extent.
Online since: June 2014
Authors: Jamaluddin Md Sheriff, Nor Azwadi Che Sidik, Nasir S. Hassen
Effect of Nozzle Angleson Spray Losses Reduction Nasir S.
The nozzle angle 65° gave the highest drift reduction compared to the other nozzle angles.
The number of variables involved in any field studies makes data interpretation difficult, so wind tunnel studies have been advocated to characterize the effect of operating parameters on the risk of spray drift with a high degree of reliability because weather conditions cannot be controlled in the field[4-8].
The objective of this study is to examine effect of spray nozzle angle on spray losses reduction.
The data from the spray tests were collected and analysis of variance (ANOVA) on the spray drift was carried out, using a mathematical model for a completely randomized design.
Online since: January 2014
Authors: Xuan Cang Wang, Wei Yu, Yan Nan Zhang, Zhi An Feng
The proper value of temperature gradient, reliably coefficient, stress reduction coefficient, comprehensive coefficient and the effect of load position in structure calculations were studied respectively.
As can be seen from formula(3), ultimate load is related to bending rigidity of concrete slab , maximum temperature stress , reliably coefficient , stress reduction coefficient and comprehensive coefficient.
Utilizing the nonlinearity transformation equation (6) of the pavement surfaceand the environment temperature , the local day-to-day temperature data of 52 years (1960~2011) were transformed to surface temperature data
Thus, the influencing factors of ultimate axle load are only reliably coefficient, stress reduction coefficient and comprehensive coefficient .
Reasonable determination of stress reduction coefficient.
Online since: May 2007
Authors: Sang Mock Lee, Jang Hoon Chung
Cathode research in DMFC technology is mainly focused on developing more selective and methanol-tolerant catalysts for oxygen reduction.
These catalysts were electrochemically tested for their activity towards methanol oxidation and oxygen reduction in a half cell arrangement.
Completing reduction of the precursor, nitrogen gas was streamed in order to remove hydrogen.
Several standard composites were prepared by same method from general precursor for comparison of data.
As shown in Fig.2, these data indicate that PtTm-C is less active toward O2 reduction than Pt-C.
Online since: July 2011
Authors: Yang Yang
The basic idea behind this sort of approaches is to approximate the matrix derived from the noisy data, with another matrix of lower rank from which the reconstructed signal is derived.
Equation (6) can be rewritten as (7) Comparing (3) and (7) yields (8) and (9) Since the matrices and are respectively the approximation of the initial clean data matrix and the noise matrix, we can reduce the effect of additive noise from the original signal via removing or decreasing the subspace and utilizing the matrix in reconstruction of the enhanced data matrix.
In this method a polynomial is fit to a number of consecutive data points from the time-series.
They include the number of rows in the Hankel data matrix “1”, the optimum threshold point needed for space subdivision “”, the degree of polynomial , “”and the window size of the Savitzky-Golay filter “” used for filtering the singular vectors.
In the traditional SVD and GSVD approaches, the singular values of the data matrix are filtered for speech enhancement, while the singular vectors of the noisy data matrix are not enhanced.
Online since: April 2014
Authors: Shu Lu Zhang, Qiang Zhang, Dong Sheng Zhou
Because of the complexity of human motion, one-time motion capture data is insufficient to cope with all the movement.
Qu et al [2] adopted Gaussian model to reduce the dimension of motion data, which maps the motion data into a low-dimensional hidden space, we could detect the segmentation points in this low-dimensional space.
JING Shu-xu et al [3] proposed a method to find the internal structure of motion data by PCA method.
Our approaches for motion segmentation We use the LLE algorithm to get the feature curve of the original data, Sam T.
The motion capture data used for the experiments is from CMU.
Online since: October 2012
Authors: Khairiah K. Turahim, Syazwani A. Rahim, Asan G.A. Muthalif
It involves transmission of data from a transmitter to a receiver.
In order to achieve successful data transmission, a continuous alignment between the transmitter and receiver telescope is needed.
Introduction Free-space optics (FSO) communication is a technology that uses light to transmit data through free space.
For an FSO link to successfully transmit data, it requires a continuous alignment between the transmitter and receiver [1].
Then the data are passed to controller which calculates the required external forces or displacement and send signals to control the actuators.
Online since: October 2010
Authors: Byung Wan Jo, Ji Sun Choi, Seok Won Kang
An Experimental Study on the Characteristics of Chemically Synthesized Nano-Cement for Carbon Dioxide Reduction Byung-Wan Jo1,a, Ji-Sun Choi2,b, Seok-Won Kang3,c Professor, Dept. of Civil Engineering, Hanyang University, Seoul, Korea.
a joycon@hanmail.net b opt506@naver.com c hastally@nate.com Keywords: CO2 reduction, Chemical synthesis, Alkali activation, Compressive strength, Highly functional construction material Abstract .Cement is becoming a principal factor in air pollution because of the creation of CO2 during its manufacturing.
First of all, based on the selection of the “Kyoto protocol” to reduce greenhouse gases in order to prevent global warming, a practical plan for the reduction of CO2 and greenhouse gases is urgent, as the results are still insufficient.
Arteaga, “Determination of kinetic equations of alkaline activation of blast furnace slag by means of calorimetric data”, J Thermal Analysis 52, 1998, pp. 945-955
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