How to show Hidden System Files and Folders on Flash Drives

Computer viruses are programs that copy themselves automatically and may destroy
your files. One of the effect of a virus on a usb flashdrive is turning all its contents
to Protected Operating System Files so that if you insert it to a computer, you can't
see any files inside because it is hidden. Showing the hidden files on the folder
options is not enough, you have to uncheck the 'Hide Protected System Files' option
as well. But this will not solve the problem. You can only see your files temporarily.
To overcome this, follow the instruction below.

1. Open command prompt.
2. Type:    attrib -S -H G:\*.* /S /D /L

* This will unset the attribute "Protected Operating System Files" on the files from a usb
  flashdrive on drive 'G:'.

Structural analysis for vertical concrete canal linings.

Assumptions:
1. No water inside the canal and the embankment outside
is up to the top bank of the canal.
2. Soil is saturated.

Procedure of analysis:

1. Compute for pressure at canal bottom using the formula:
         (1-sin(A))
Ph = ----------- x SoilWeight x CanalHeight
 (1+sin(A))
A = Angle of internal friction of soil