Study on the Method Used to Display Self-fading Lines and Erasable Lines
Biao Li1, Guoliang Ouyang1, Lijuan Yao2
1Department of Document Examination, National Police University of China, No. 83 Tawan Str., Shenyang City, 110854, China.
Abstract:
Two new kinds of writing tools are popular in China's market. One is a self-fading pen, and another is an erasable pen. The ink of the two kinds of writing tools has a remarkable characteristic that it can gradually fade or disappear under heat or be rubbed off. How to reveal the disappeared written lines is a very important question for document examiners. In this article, three series of ink line samples were made with five types of self-fading pens, 18 types of erasable pens, and three types of papers. Temperature, humidity, and lighting are known as influential factors of the process, and the effect of fading was examined. Luminescence, ultraviolet (UV), sidelight, electrostatic indentation development,low temperature, and solution revealing methods are found to be effective methods used to reveal the disappeared written lines. The best operating conditions for each method were obtained from the conducted experiments.
Related Concept Videos
01:16Cell Lines
01:23Lossless Lines
01:22Lossy Lines and Overvoltages
Attenuation
When constant series resistance and shunt conductance are present, voltage and current equations are modified. The propagation constant indicates that voltage and current waves consist of both forward and backward traveling components. These waves attenuate as they propagate, with the attenuation factor related to the resistance and conductance. In a...
01:25Electric Field Lines
The solution to this problem is to use electric field lines, which are not vectors but...
01:19Magnetic Field Lines
Magnetic field lines follow several hard-and-fast rules:
01:25Properties of Electric Field Lines
For one, the electric field of a positive charge must originate from it. That is because its electric field points away from it. Moreover, since the magnitude of the field asymptotes to zero at infinity, the...