In this lesson, we analysed the blood splatter made on a piece of butcher sheet by Clara's group, comprising of her, Mavis, Zek Min and Cynthia. After analysing, we were supposed to make a video, explaining how the blood splatters were made. Even though we were only supposed to have 25 minutes to complete discussion and video-making, our class took quite a long time of an hour(?).
HERE'S THE VIDEO! enjoy (:
My group members: Audrey, Jia Min, Yuexin and I.
Saturday, August 13, 2011
Blood Splatter! Lab Lesson Data
We conducted 2 experiments in that lesson, namely to find out 2 things:
1) To investigate how the diameter of the blood stains vary with the height
2) Investigate how the shape of the blood stains vary with the angle of impact
The photos have already been uploaded in the previous post (:
DATA:
1) To investigate how the diameter of the blood stains vary with the height
2) Investigate how the shape of the blood stains vary with the angle of impact
The photos have already been uploaded in the previous post (:
DATA:
Friday, August 12, 2011
Blood Splatter Practical
This is my iphoto book! :D filled with pictures taken during practical itself (: I know the last few pages aren't filled but i cant seem to delete them because iPhoto doesnt allow me to ):
anyway, ENJOY!
anyway, ENJOY!
Tuesday, August 9, 2011
Chromatography and Flames
Chromatography Experiment!
Procedure:
1. Cut rectangular pieces of each digit out of cheque paper, keeping in mind order of digits.
2. Use forceps to transfer each piece into each Microfuge tube.
3. Pour a little ethanol (NOT TOO MUCH) into Microfuge tubes, just enough to cover digits.
4. Gently shake Microfuge tubes.
5. Draw pencil line 2 cm from width of each strip of chromatography paper and label each one (e.g marker ink, digit no. 1)
6. Use capillary tube to transfer ink from each Microfuge tube to the pencil line of each chromatography paper strip.
7. Use the marker (i.e. 1 or 2) to dot on one of the chromatography papers.
6. Fill each boiling tubes with 1ml of distilled water.
7. Dip each chromatography paper into each boiling tube so that the pencil line is a little above the water level. Use wooden peg to hold the paper in place.
8. When the solvent is about to reach the wooden peg, quickly remove the paper from the boiling tubes and mark the solvent fronts.
9. Calculate Rf values and compare.
PICTURES! (:
Flames hands-on!
Copper (II) Nitrate
Barium Nitrate
Sodium Nitrate
Lead (II) Nitrate
Potassium Nitrate
Calcium Chloride
Fascinating pictures of MS TAN conducting some experiments!
Procedure:
1. Cut rectangular pieces of each digit out of cheque paper, keeping in mind order of digits.
2. Use forceps to transfer each piece into each Microfuge tube.
3. Pour a little ethanol (NOT TOO MUCH) into Microfuge tubes, just enough to cover digits.
4. Gently shake Microfuge tubes.
5. Draw pencil line 2 cm from width of each strip of chromatography paper and label each one (e.g marker ink, digit no. 1)
6. Use capillary tube to transfer ink from each Microfuge tube to the pencil line of each chromatography paper strip.
7. Use the marker (i.e. 1 or 2) to dot on one of the chromatography papers.
6. Fill each boiling tubes with 1ml of distilled water.
7. Dip each chromatography paper into each boiling tube so that the pencil line is a little above the water level. Use wooden peg to hold the paper in place.
8. When the solvent is about to reach the wooden peg, quickly remove the paper from the boiling tubes and mark the solvent fronts.
9. Calculate Rf values and compare.
PICTURES! (:
Flames hands-on!
Copper (II) Nitrate
Barium Nitrate
Sodium Nitrate
Lead (II) Nitrate
Potassium Nitrate
Calcium Chloride
Fascinating pictures of MS TAN conducting some experiments!
FINGERPRINTING!
Order of fingerprinting methods in our FIRST lab practical:
1) Iodine Fuming
2) Ridges and Pores Activity (wood glue)
3) Cyanoacrylate (Superglue) Fuming Method
4) Powder Dusting Method
Iodine Fuming!
Fingerprints can be seen using this method because natural body fats and oils in the larent print temporarily absorb the iodine vapours, resulintg in a change in colour, often from colourless to dark brown. However, this change fades after a while as the iodine that was absorbed eventually dissipated into the atmosphere.
Placing filter paper into the glass jar with iodine fumes:
Close-up:
Product (the one on the left is Audrey's and mine's on the right)
Cyanoacrylate (Superglue) Fuming Method
Superglues typically contain methylcyanocrylate or ethylcyanoacrylate which react with traces of amino acids, fatty acids and proteins in the latent fingerprint and the moisture in the air to produce a visible sticky white substance along the ridges of the fingerprint.
order of fingerprints: audrey's mine michelle ang's and heidi's
Ridges and Pores Activity
A friction or epidermal ridge is a raised porton of the skin on the fingers and toes. Impressions of fingerprints may be left behind on a surface by natural secretions of sweat from glands that are present in friction ridge skin.
When the glue is undried:
The dried version:
Last but not least, the powder dusting method!
Oils and perspiration from the common residue on finers that get transferred when a print is made. When the powder is applied to the suface with the print, it sticks to the oils and brings out the ridge patterns.
its now pasted onto my worksheet!
MY FINGERPRINT DATABASE!
1) Iodine Fuming
2) Ridges and Pores Activity (wood glue)
3) Cyanoacrylate (Superglue) Fuming Method
4) Powder Dusting Method
Iodine Fuming!
Fingerprints can be seen using this method because natural body fats and oils in the larent print temporarily absorb the iodine vapours, resulintg in a change in colour, often from colourless to dark brown. However, this change fades after a while as the iodine that was absorbed eventually dissipated into the atmosphere.
Placing filter paper into the glass jar with iodine fumes:
Close-up:
Product (the one on the left is Audrey's and mine's on the right)
Cyanoacrylate (Superglue) Fuming Method
Superglues typically contain methylcyanocrylate or ethylcyanoacrylate which react with traces of amino acids, fatty acids and proteins in the latent fingerprint and the moisture in the air to produce a visible sticky white substance along the ridges of the fingerprint.
order of fingerprints: audrey's mine michelle ang's and heidi's
Ridges and Pores Activity
A friction or epidermal ridge is a raised porton of the skin on the fingers and toes. Impressions of fingerprints may be left behind on a surface by natural secretions of sweat from glands that are present in friction ridge skin.
When the glue is undried:
The dried version:
Last but not least, the powder dusting method!
Oils and perspiration from the common residue on finers that get transferred when a print is made. When the powder is applied to the suface with the print, it sticks to the oils and brings out the ridge patterns.
its now pasted onto my worksheet!
MY FINGERPRINT DATABASE!
Wednesday, July 20, 2011
Solving a Virtual Mystery Case
CLUES COLLECTED
Footwear impressions allow you to match the impression with actual footwear owned by suspect.
Toolmark impressions allow you to match the impression with actual tools owned by suspect.
Paint examination allows you to match a tool to the crime scene, when the tool is found.
Computer composites can help with suspect identification.
Hair analysis enables comparisons with the suspect's hair or with hair found on the suspect's clothing
Document analysis can verify the authenticity of a document and who the author is.
Fingerprint analysis is still the predominant means of establishing positive identification.
Fiber analysis rests on the principle that whenever two individuals are in contact, materials (dust, paint, cloth...) are exchanged at a microscopic level.
Blood stain pattern analysis tells you how a crime was committed.
Blood analysis lets you identify a victim or a suspect, because DNA is unique to each individual.
Wound analysis can help with identifying the murder weapon.
Pathology allows you to establish time of death and compare with suspect's schedule.
Footwear impressions allow you to match the impression with actual footwear owned by suspect.
Toolmark impressions allow you to match the impression with actual tools owned by suspect.
Paint examination allows you to match a tool to the crime scene, when the tool is found.
Computer composites can help with suspect identification.
Hair analysis enables comparisons with the suspect's hair or with hair found on the suspect's clothing
Document analysis can verify the authenticity of a document and who the author is.
Fingerprint analysis is still the predominant means of establishing positive identification.
Fiber analysis rests on the principle that whenever two individuals are in contact, materials (dust, paint, cloth...) are exchanged at a microscopic level.
Blood stain pattern analysis tells you how a crime was committed.
Blood analysis lets you identify a victim or a suspect, because DNA is unique to each individual.
Wound analysis can help with identifying the murder weapon.
Pathology allows you to establish time of death and compare with suspect's schedule.
Tuesday, July 19, 2011
Awareness Test
Number of tosses in the white team: 13
Reflection: While everyone was intently focusing on the number of tosses of the ball was made by the white team, we failed to notice a man dressed in a bear suit, moonwalking across the screen. This was through this that i realised that while one is preoccupied on an object or movement, they will have almost completely no awareness as to what was transpiring around them except the fixated object.
Reflection: While everyone was intently focusing on the number of tosses of the ball was made by the white team, we failed to notice a man dressed in a bear suit, moonwalking across the screen. This was through this that i realised that while one is preoccupied on an object or movement, they will have almost completely no awareness as to what was transpiring around them except the fixated object.
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