crime busters science olympiad

Arch

a hill with no deltas

tented arch

an arch with a sharp corner at the top point

plain arch

an arch with a more rounded top point

loop

a beanish shape with one delta

ulnar loop

a loop pointing towards the pinky

radial loop

a loop pointing towards thumbs

whorl

a circle like shape with 2 or more deltas

plain whorls

has 2 deltas and at least one ridge making a complete circuit

central whorls

consists of at least one re-curing ridge or an obstruction at right angles to the line of flow

double loop whorls

consists of 2 separate and distant loop formations with 2 separate and distant shoulders for each core

accidental whorls

consists of 2 different types of patterns with the expeptation of the plain arch

Vegetable fibers

Burn Test Observations: (cotton and flax, Cellulose based)

1. Does not shrivel away from flame

2. Ignites immediately with contact to flame, burns really quickly and readily in flame.

3. Continues to burn, has an "afterglow" when removed from flame until fibre expended

4. Smells likes burning paper

5. Ashes are fluffy, small, white to grey-coloured

Synthetic fibers

Burn Test Observations:

1. Won't light in flames but melts close to the flame.

2. spirals back to stick to the tweezers.

3. Smells of black smoke like burning plastic, slightly sweet.

4. No Ashes, the fibers curl back.

A wide variety of synthetic fibers all have trade

names such as Nylon, Orlon, Dacron, Vinyon, Aralac, Acrilan, Velon, Dynel, Banlon and Lycra. Like rayon, these fibres resemble silk, and under the microscope look like smooth, lustrous, regular shaped cylinders. Synthetic fibers are easily identified because of their uniform thickness (the thickness of natural fibers varies).

Wool

1. Wool is the most commonly used animal fiber, it normally is obtained from the soft, hairy covering of sheep and sometimes goats.

2. The fiber is stretchable, easily absorbs water, soft and long lasting, doesn't wrinkle and springs back into shape, and has short fibers.

3. Wool fabric is known for its ability to "breathe" keeping wearers warm in the winter and somewhat cool in warmer weather.

4. Wool picks up static electricity easily when rubbed.

5. Dissolve in bleach.

6. Under the microscope, the wool fiber looks like a long cylinder with distinctive scales on it. The fiber is very curly and springy.

Burn Test: Hard to light, wouldn't stay lit, smells of burning hair. The ashes is very hard, stuck to the fiber sample.

Silk

1. Another common animal fiber, was once quite popular, but has been replaced to a great extent by such synthetic fibers as Nylon, Orlon, and Dacron.

2. Silk is made by the mulberry silk worm when spinning its cocoon.

3. Will dissolve in bleach.

4. Under the microscope the silk fiber appears as a thin, long, smooth and shiny cylinder. The fiber is double strands. The fabric is lightweight but can keep its wearer warm

Burn Test: Rapidly burns with uneven flames, smells of burning hair, the ashes are very brittle.

Cotton

1. Cotton is the most widely used plant fiber, it's the hairs found on the seeds of the cotton plant.

2. The fabric that cotton produces is soft, absorbs water, and wrinkles easily. Cotton is a fabric that is light and cool.

3. The cotton fibers (use a few strands of absorbent cotton) when examined under a microscope will look like a flattened, irregular, twisted ribbon with short fibers.

4. Will Not dissolve in bleach.

Burn Test Observation: A steady orange flame, turns black. smells like burning leaves, ashes is very crumbly, falls apart easily.

Linen

The strongest vegetable fiber,, made from the stalk of the flax plant, its two to three times stronger then cotton!. The fiber is long, shiny, and smooth, has poor elasticity, gets softer with use, absorbs water, . and wrinkles easily. Under the microscope it looks like miniature bamboo. Linen gets softer with use and considered a cool fabric for warmer climate.

Point out that linen is often used to make handkerchiefs, tablecloths, napkins, summer clothing and blouses.

Hemp

This is a plant fiber that is similar to flax (linen) and ramie(but not as fine), therefore it possesses similar properties. Hemp excels in fiber length, strength, durability, absorbency, antimildew and antimicrobial properties. This fiber can be of different qualities, the highest coming from Cannabis Sativa, and lower qualities being Sisal and Manilla Hemp.

Hemp works best in fabrics when mixed with other fibers, although high quality Hemp fabric is produced and wearable, although easily wrinkled.

This fabric also withstands water better then any other textile product and are used to make carpet backing rope, twine and sacks.

Rayon

Rayon is one of the first successful artificial man-made fibers, although it is not considered synthetic. It is made from cellulose (plant). When manufactured, the rayon fibers resemble silk. This fiber is just as versatile and comfortable as natural fibers, such as cotton.

Under the microscope, the rayon fiber looks like a smooth, lustrous, glass-like cylinder, easily stretchable, doesn't wrinkle, is soft and absorbent and easy to dye, but is not a good insulator. Rayon can be made into cloth that is hard to distinguish from silk, cotton, linen, or wool.

Burn Test: Burned with a steady, rapid orange flame, smells of burning leaves, but no ash present.

Acetate

ACETATE is a created from wood. Under the microscope there are grooves that run the length of the fibers. Acetate is soft, smooth, and will melt under a hot iron. It does not absorb water. The fabric is cool

Nylon

NYLON is derived from coal. The fibers under the microscope are smooth and clear rods. Nylon is shiny, tough, stretchable and melts under a hot iron. The fibers are nonabsorbent, quick drying, and doesn't wrinkle. the fabric is cool but clammy.

Acrylic

ACRYLIC is made from petroleum. Under the microscope the fiber is dog-bone shaped with apparent cut ends. The fabric is lightweight, warm, and quick drying.

Polyester

POLYESTER is derived from petroleum. Under the microscope the rod shaped fiber looks like nylon but is not clear. The fiber does not wrinkle, is silk-like, strong, and absorbent.

Spandex

Spandex will expand to 54 times its original size

Glass Fiber

1. Glass fibers are made by stretching melted glass into fine filaments, which are spun into thread for weaving into cloth.

2. Lightweight glass fibers are used to make long lasting windows curtains, drapes, and lamp shades. 3. Heavier glass fabrics are used to make fireproof theater and school curtains.

Asbestos

1. Asbestos is the name given to a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven to make asbestos cloth.

2. These fibers

are not affected by heat or chemicals and do not conduct electricity.

3. Asbestos cloth was used in fireproof theater curtains and protective suits for use by fire fighters.

4. It was also used as a building material, brake pads and a range of other products.

5. It is now know that the fibers of asbestos are a dangerous irritant. Even exposure to small amounts of asbestos dust can lead to a range of illnesses such as asbestosis, a serious lung inflammation

caused by asbestos exposure, and Mesothelioma a cancer of the chest and abdomen.

DNA pairing

'A' to 'T' and 'C' to 'G'.

1. nucleus DNA and mitochondria DNA

2. The main difference between nucleus DNA and mitochondria DNA is that half of the nucleus DNA came from each parent, but all of the mitochondria DNA comes from the mother. This makes tracing lineage easier through the mother.

3. The hair must have living cells from the root attached to it if regular nucleus DNA tests are to be run, but if mitochondrial DNA is to be tested, there is no such requirement. Therefore any piece of

hair can be tested.

4. Mitochondria DNA testing is the most popular test that is done on hair today in a real crime scene.

Hair Color

This property depends on the amount of melanin in hair. More melanin means darker hair, while less means lighter. Dyed Hair can be problematic for scientists because it takes away from this property.

Human Hair

Made of the medulla, the cortex, and the cuticle. Comes in many different colors, sizes, shapes. Thick compared to other animals.

Cat Hair

This is a lot finer than human or dog hair.

Dog Hair

There are two main kinds of these: Inner Layer, which is more fine and curly, and outer layer, which is a lot more coarse and rigid. It is fairly thick.

Animal Fibers

Silk and Wool are among these kinds of fibers. Wool smells like burnt hair and has short fibers. They often have fuzz sticking off of their edges and are twined. They can dissolve in bleach.

Vegetable Fibers

Cotton and Linen are included in this group. They don't dissolve in bleach, and, like their natural counterpart, have fuzz sticking off of them. In a burn test, cotton burns but doesn't smell burnt.

Man-Made Fibers

Polyester, Nylon, Dacon, Acetate are some of them, but there are many. They burn off first in a burn test. These kinds of fibers are very smooth since they are synthetic. They are longer than other fibers.

Whorl Fingerprint

Looks like a target. The delta points are on the edges of the center (there are two).

Tented Arch

The more defined version of a certain kind of fingerprint, because it slopes up and down quickly like a hill. Doesn't have a delta point. It is the least common kind of fingerprint.

Rounded Arch

The less defined version of this kind of fingerprint, it is more round.

Loop Fingerprint

The lines move right, swirl around a center point, and then move backward. It has one delta point to the bottom left of the center. It is the most common kind of fingerprint.

Sodium Acetate

A powder with irregularly shaped crystals. It has a white color. It is soluble with a pH of 9. It is endothermic (absorbs heat) and has a sweet odor.

Sand

This substance is usually white with black specks and is insoluble. It has a pH of 7 and has a bad odor when is reacts with iodine.

Calcium Carbonate

Makes up limestone. It is a white powder with a pH of 7 and is insoluble. HCL makes it fizz up and it is rather airy and holey.

Salt

Has large square grains, is white and soluble, with a pH of 7. It may have a delayed reaction with iodine since iodine is often in it. Composed of Sodium Chloride.

Vitamin C

It is made of white grains. The pH is very acidic at 2. It is soluble and iodine can clear it. It may have a distinctive tint and smell if it comes from a tablet.

Sugar

It is made of grains and is white and is amazing. It is soluble with a pH of 7. It is rather similar to salt, except the grains are more rounded and also life wouldn't be complete without it.

Flour

It is classified as "off-white" because it is not perfectly white. It clumps up in water and has a pH of 7. It blackens iodine and makes it clump together.

Cornstarch

It is white, powdery with a pH of 7. It forms a solid/liquid substance when put in water. It turns purple when mixed with iodine.

Gelatin

It is made of tan grains and swells up into a gel-like substance in water. It has a pH of 7,

Alka Seltzer

A soluble white powder that has a pH of 9 and is highly reactive- it fizzes up when mixed with anything, including Hydrochloric Acid and Iodine.

Yeast

It is tan and pellet-y and insoluble. It normally smells like bread.

Baking Soda

It is powdery, white, and slightly basic. It has a sort-of rough texture and fizzes up for a long time in HCL. It is soluble.

Gypsum

It is powdery and white and insoluble in water, with a pH of 7. While it doesn't react much with HCL and Iodine, it hardens in water. It comes from the mineral of the same name.

Lemon Juice

This liquid is rather acidic at a pH of 3, and has a strong citrus scent. Pulp is usually found mix in with it.