Corrosion of Zinc By Differential Aeration★

CORROSION ◽  
1958 ◽  
Vol 14 (5) ◽  
pp. 55-58
Author(s):  
G. BlANCHI
Keyword(s):  
Water Level ◽  
Level Line ◽  
Cathodic Reduction ◽  
Local Corrosion ◽  
Oxygen Flux ◽  
Test Time ◽  
Test Results ◽  
Time Test ◽  
Zinc Distribution

Abstract Tests were made to study the differential aeration corrosion of zinc in molar NaCl solutions under varying conditions of aeration, pH, and length of test time. Test results led to the conclusion that formation of differential aeration macrocells is due to passivity of zinc on the zones of the specimen where cathodic reduction of oxygen takes place, and that the principal process of corrosion is accompanied by local corrosion processes at the cathodic and anodic areas of the macrocell. With buffered solutions which do not permit the passivation of zinc, distribution of corrosion changes radically, a localized attack taking place at the water level line where the oxygen flux is at a maximum.3.6.2

Framework and performance analysis of college English testing system based on data mining technology

2021 ◽  
pp. 1-11
Author(s):  
Liu Narengerile ◽  
Li Di ◽  
Keyword(s):  
Data Mining ◽  
Test System ◽  
Test Time ◽  
Testing System ◽  
Test Results ◽  
System Software ◽  
Examination System ◽  
Mining Technology ◽  
College English ◽  
And Performance

At present, the college English testing system has become an indispensable system in many universities. However, the English test system is not highly humanized due to problems such as unreasonable framework structure. This paper combines data mining technology to build a college English test framework. The college English test system software based on data mining mainly realizes the computer program to automatically generate test papers, set the test time to automatically judge the test takers’ test results, and give out results on the spot. The test takers log in to complete the test through the test system software. The examination system software solves the functions of printing test papers, arranging invigilation classrooms, invigilating teachers, invigilating process, collecting test papers, scoring and analyzing test papers in traditional examinations. Finally, this paper analyzes the performance of this paper through experimental research. The research results show that the system constructed in this paper has certain practical effects.

Frost Formation and its Density Behavior on Various Surfaces

2001 ◽  
Author(s):  
Cheolhwan Kim ◽  
Jongmin Shin ◽  
Alexei V. Tikhonov ◽  
Samchul Ha ◽  
Bongjun Choi
Keyword(s):  
Surface Energy ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Test Time ◽  
Test Results ◽  
Plate Temperature ◽  
Specific Test ◽  
Frost Formation ◽  
Frost Layer ◽  
Density Behavior

Abstract An experimental study has been conducted to investigate the effects of surface energy on frost formation. Test samples with three different surfaces of which Dynamic Contact Angles (DCA) are 23, 55 and 88 degrees are installed in a wind tunnel and exposed to a humid airflow. The thickness and the mass of frost layer are measured and used to calculate frost density while frost formation is visualized simultaneously with their measurements. Results show that frost density increases as time increases at specific test conditions. The air Reynolds number, the airflow humidity and the cold plate temperature are maintained at 12,000, 0.0042 kg/kg and −20 degrees Celsius, respectively. The surface with a lower DCA shows a higher frost density for a two-hour test, but no differences in frost density have been found after two hours of frost generation. Empirical correlations for thickness, mass and density are proposed as the functions of test time and surface energy. Visualization of frost generation was in good agreements with test results.

Test Reliability of Impurity Parameters of Uster AFIS

2011 ◽  
Vol 331 ◽  
pp. 516-527
Author(s):  
Peng Zi Sun ◽  
Ji Peng Cao
Keyword(s):  
Statistical Analysis ◽  
Test Reliability ◽  
Test Time ◽  
Test Results ◽  
Analysis Method ◽  
Sample Weight ◽  
Reliable Test ◽  
Sampling Process ◽  
Statistical Analysis Method ◽  
Card Sliver

This paper presents test reliablity of Uster AFIS for impurity test by calculating the Reliable Test Time (hereinafter referred to as RTT) and CV% of test results. The CV% value of test results of impurity-related parameters in card sliver obtained in 8 experiments totally with 313 different plans were calculated. By statistical analysis method, the reliable test time of AFIS for some impurity-related parameters was estimated. It is concluded that the impurity result obtained by 10-time tests with AFIS was inaccurate. The reasons for this are that the sample weight is too small, the impurity is unevenly distributed and the impurity in card sliver may have some loss in the manually-sampling process.

Influence of particle size distribution, test time, and moisture content on sandy stratum LCPC abrasivity test results

2020 ◽  
Vol 80 (1) ◽  
pp. 611-625 ◽  
Author(s):  
Zhengyang Sun ◽  
Zhiyong Yang ◽  
Yusheng Jiang ◽  
Hongji Gao ◽  
Kuanda Fang ◽  
...  
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Test Time ◽  
Test Results

Dynamic Measurement of Bearing Radial Clearances

2005 ◽  
Vol 295-296 ◽  
pp. 361-366 ◽  
Author(s):  
Yu Xue Chen ◽  
S.N. Yang
Keyword(s):  
Measurement Accuracy ◽  
Systematic Errors ◽  
Dynamic Measurement ◽  
Outer Ring ◽  
Radial Clearance ◽  
Test Time ◽  
Ball Bearings ◽  
Test Results ◽  
Accuracy Measures

Outer ring tilted or offset axially, caused by improperly fixing relatively to the inner ring, will produce remarkable systematic errors in measured radial clearance of a bearing. Analyzing their effects in detail on the results of measured radial clearances, they are found to be the main sources affecting the measurement accuracy. Measures for removing them are proposed. Based on these, a novel type of instrument for measurement of radial clearances of ball bearings has been developed. It could avoid the two kinds of systematic errors. The measuring principle, structures and working procedures of the instrument are presented. Test results show that the test time is less than 15 seconds per a part and the indication stability is between ±1.0 µm.

Thermal Hydraulic Test of Advanced Fuel Bundle With Spectral Shift Rod (SSR) for BWR: Steady State and Transient Test Results and Analysis

2012 ◽  
Author(s):  
Takao Kondo ◽  
Kazuaki Kitou ◽  
Masao Chaki ◽  
Yukiharu Ohga ◽  
Takeshi Makigami
Keyword(s):  
Steady State ◽  
Water Level ◽  
Simulation Analysis ◽  
Spectral Shift ◽  
Test Results ◽  
Analysis Method ◽  
Fuel Bundle ◽  
State Test ◽  
Shift Effect ◽  
Steady State Test

Japanese national project of next generation light water reactor (LWR) development started in 2008. Under this project, spectral shift rod (SSR) is being developed. SSR, which replaces conventional water rod (WR) of boiling water reactor (BWR) fuel bundle, was invented to enhance the BWR’s merit, spectral shift effect for uranium saving. In SSR, water boils by neutron and gamma-ray direct heating and water level is formed as a boundary of the upper steam region and the lower water region. This SSR water level can be controlled by core flow rate, which amplifies the change of average core void fraction, resulting in the amplified spectral shift effect. This paper presents the steady state test with varied SSR geometry parameters, the transient test, and the simulation analysis of these steady state and transient tests. The steady state test results showed that the basic functioning principle such as the controllability of SSR water level by flow rate was maintained in the possible range of geometry parameters. The transient test results showed that the change rate of SSR water level was slower than the initiating parameters. The simulation analysis of steady state and transient test showed that the analysis method can simulate the height of SSR water level and its change with a good agreement. As a result, it is shown that the SSR design concept and its analysis method are feasible in both steady state and transient conditions.

Design of the Wireless Monitoring Unit for Underground Rail Vehicles

2013 ◽  
Vol 694-697 ◽  
pp. 1064-1067
Author(s):  
Guang Long Xu ◽  
Jian Hua Rao ◽  
Ken Yang ◽  
Tao Wang
Keyword(s):  
Monitoring Station ◽  
Mining Engineering ◽  
Test Results ◽  
Wireless Monitoring ◽  
Modbus Protocol ◽  
Time Motion ◽  
Rail Vehicles ◽  
Time Test ◽  
Upper Computer ◽  
Ground Monitoring

A wireless monitoring unit is designed for underground rail vehicles (URVs) in fields of mining engineering and underground construction. The unit consists of transmitting subsystem and receiving subsystem which are connected by using radio-frequency (RF) technique. Transmitting subsystem acquires and transmits the real-time motion parameters and state of a URV. Receiving subsystem transfers the data to ground monitoring station by RS-485 bus based on Modbus protocol. The upper computer in ground monitoring station displays and stores monitoring results of the URV, which enables the staff to obtain the information of a URV in time. Test results prove that the wireless monitoring unit can work steadily.

Research on Heavy-Duty Coating Protection System of Magnesium Alloy

2015 ◽  
Vol 1119 ◽  
pp. 525-528
Author(s):  
Ru Tang Yan ◽  
Yuan Yuan Li ◽  
Chun Wei She ◽  
Hua Geng Li ◽  
Hua Pan Li
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Protection System ◽  
Test Time ◽  
Test Results ◽  
Ageing Test ◽  
Micro Arc Oxidation ◽  
Resistance Performance

The poor corrosion resistance of magnesium alloys become the bottleneck restricting its development. Based on micro-arc oxidation (MAO) technology and the characteristics of fluorocarbon coating the surface of magnesium alloy build a high corrosion protection system, namely: Based on micro-arc oxidation coating fluorocarbon coatings. The formation of the composite coating through the resistance to ageing test through the resistance to ageing test, acid and alkali experiment and salt spray test results show the excellent corrosion resistance performance. Among them, the resistance to salt spray test time can reach 1500 h, which breaks the bottleneck of magnesium alloy corrosion resistance of 1000 h.

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