The Pilot Model of Capacity of Supplement for Groundwater by Rainfall Resource in Dormitory Area of Vnu-HCM

Abstract

This paper reveals the capacity of supplement for groundwater by rainfall resource based on the monitoring and analyzing result of rainfall, evaporate, groundwater table of central-collecting well and monitoring wells as well as the geophysical test result in dormitory area of VNU-HCM from November 2007 to February 2009.

Design and Manufacture of Welding Fumes Electrostatic Precipitator and Parameter Study on Filtration Performance

“…Furthermore, a large number of experiments must be performed as the number of process parameters increases. To solve this problem, the Box-Behnken design method uses a special design of orthogonal blocks to study the entire parameter with only a few experiments [5]. The Box-Behnken design is an independent secondorder design of experiments that does not contain TNT or TRT design.…”

“…Fig. 12 Box-Behnken experiment design with three-factor [5] The Box-Behnken design is symmetric but not orthogonal. Therefore, when we remove the coefficients of the regression equation that are not significant, must recalculate the remaining coefficients.…”

“…The experimental parameters limited by electrical power, the gas flow velocity and the dust collector tube diameter, Table 2 shows the parameters affecting the filtration performance for low, medium and high levels, respectively in experiment. (1) Open the exhaust fan, set the exhaust fan to reach the gas flow velocity of 10m/s (2) Put the workpiece on the table, welding with the constant welding procedure specification (3) Measure the dust concentration value when not using the electrostatic filter system, perform the measurement three times to get the average value (4) Clean the tube and filter box, install the collector electrode according to the experimental sequence (5) Open the exhaust fan, set the exhaust fan parameters according to the experimental sequence (6) Adjust the power of the electrostatic generator according to the experimental sequence (7) Put the workpiece on the welding table and perform welding as step (2) (8) Counter the particle for 50 seconds, record the results (9) Clean the tube and filter box, and (10) Repeat from step 4 until the number of experiments is complete.…”

“…The results of the performance test with five number of measurements are shown in Table 3. Choose the level of significance q = 0.05  Reliability probability p = 0.95 Level of significance is 95% and the number of degrees of freedom: f = N-1 = 5-1 = 4  t = 2.78 (Student table [5]); and number of experiments, N = 5 The average value:…”

Preparation of platinum nanoparticles in liquids by laser ablation method

“…We have previously reported our investigations on the formation of silver and gold nanoparticles by laser ablation in several liquids [10,11]. In this paper, we report our investigations of Pt NPs preparation in clean and biologicallyfriendly liquids such as pure water, ethanol and TSC solution in water by laser ablation.…”