Quiz 3

Question 1

Definition of porous substance

Answer 1

absorbent, permeable to liquid or gases

Question 2

Definition of amino acid

Answer 2

organic substances that combine to form proteins

Question 3

On a porous substrate what are the factors that would cause it to go in deeper or not as deep

Answer 3

• higher smoothness values results in lower depths of penetration
• how porous the substrate is & its environment

Question 4

What chemical would leave the colour of Ruhemann’s purple?

Answer 4

Ninhydrin

Question 5

After something has been processed with DFO how do you complete the processing - after you dip it what do you do with it

Answer 5

heat it in an incubator at 100˚C for 20 minutes

Question 6

What are the attributes of a physical developer print?

Answer 6

• signature: dark grey to black images due to the deposition of silver metal along the latent print ridges
• good for old prints

Question 7

CA (cyanoacrylate / superglue) - what does it need to work?

Answer 7

• heat source, humidity, temperature
• vaporization (conversion of liquid to gas) & polymerization (monomer joining to create a long chain then adhering to the latent print residue)

Question 8

How does CA processing work - what’s the theory behind it

Answer 8

• selectively adhere’s to latent print residue resulting in white 3D friction ridge analysis
• effectively superglue’s the print down

Question 9

How to process prints on fabric

Answer 9

Vacuum Metal Deposition (VMD)

Question 10

The acidity and perspiration - what does it do to a cartridge case?

Answer 10

• etches the latent print into the cartridge casing, no chemical development techniques needed
• perspiration is also acidic

Question 11

What side of tape do you process first?

Answer 11

always process the non sticky side first

Question 12

Reagents such as amino black - what do they react with?

Answer 12

the proteins in blood