Forensic Science Chapter 6: Fibers Flashcards

8858848657	Synthetic fiber	Fibers that have been tampered with chemically	0
8858848658	Fibers	Common trace evidence at a crime scene, made up of twisted filaments	1
8858848659	Natural Fibers	Animal, vegetable or inorganic fibers	2
8858848660	List of artificial fibers	Rayon Nylon Acetate Spandex Acrylic Polyester	3
8858848661	List of natural fibers	Cotton Wool Silk Mohair Cashmere	4
8858848662	What was the first truly synthetic fiber to be discovered and sold?	Nylon	5
8858848663	Monomers	Repeating units of a polymer	6
8858848664	Tests for identification	1. microscopic observation 2. burn test 3. thermal decomposition 4. chemical tests 5. density 6. refractive index 7. fluorescence	7
8858848665	Fabric	A cloth material made up of fibers woven or bonded together in a distinctive manner	8
8858848666	What is an electropherogram?	Plot of results from an analysis done by electrophoresis.	9
8858848667	A gray cotton fiber was found on the red sweater of a victim. A gray cotton fiber was taken from a suspect's sweatshirt. After testing 900 gray sweatshirts, the lab found the fiber matches 45 of them. What is the probability that the crime scene fiber and that of the suspect matched simply by chance?	45/900 = 1/20 (0.05)	10
8858848668	What are the most common items left at the crime scene?	Hair and fiber.	11
8858848669	List at least four examples of synthetic fibers	Nylon, polyester, acrylic, plastic	12
8858848670	Is linen a natural or synthetic fiber?	Natural	13
8858848671	What is a polymer?	A molecule consisting of many repeating units. Can be naturally occurring or synthetic .	14
8858848672	List at least four examples of natural fibers.	Cotton, wool, linen, silk	15
8858848673	What types of tests are used to test the dye in a particular fiber?	Chemical tests or chromatography	16
8858848674	The Amanda Davies case showed the importance of what?	Fiber transfer	17
8858848675	Which fiber will fluoresce under ultraviolet light?	Cotton	18
8858848676	Who was the first person convicted on the basis of fiber evidence?	Wayne Williams	19
8858848677	Which of the following properties should be examined when comparing two fibers?	Diameter	20
8858848678	What does wool smell like when it is burned?	Burning hair	21
8858848679	Becke line	A halo-like shadow around an object immersed in a liquid of a different refractive index.	22
8858848680	Blend	A fabric composed of two or more different types of fiber.	23
8858848681	Chromatography	A method of separating components of mixtures.	24
8858848682	Plain	Simplest and most common weave.	25
8858848683	Density	Mass divided by volume.	26
8858848684	Elute	To extract one material from another.	27
8858848685	Filament	A single strand of material.	28
8858848686	Satin	A diagonal weave pattern, denim is an example.	29
8858848687	Viscosity	The resistance of liquid.	30
8858848688	Weft	The crosswise yarn	31
8858848689	Warp	The lengthwise yarn.	32
8858848690	Fibers are considered what?	Class evidence	33
8858848691	Nylon was developed when?	1939	34
8858848692	1911	Rayon	35
8858848693	1920s	Cellulose and Acetate	36