jeudi 6 février 2014

FORENSICS ORAL TASK


At the end of the 1st lesson, you have to give to the teacher a list of :
  • the 3 clues and collecting tecniques on the crime scene,
  • the 3 appliances used in the lab, 
  • and the 3 results used at the court.
At the end of the second lesson, you have to give to the teacher the scenario of the 3 scenes  in English. 
You have to underline :
  • the 3 clues and collecting tecniques on the crime scene,
  • the 3 appliances used in the lab, 
  • and the 3 results used at the court.
You have to tell us if you need specific prop and when you need to film. (The Science room is only free during the lunchbreak on Thursday and Friday from 12:00 to 12:45. YOU HAVE TO REGISTER...)
On the crime scene : 
  • 3 clues (or more) and the techniques to collect them.
  • Describe and explain more precisely a technique by using  scientific vocabulary. 

 In the lab :
  • 3 appliances used to analyse the clues.
  •  Describe and explain more precisely a technique by using  scientific vocabulary. 
 At the court:
  • Use 3 results of your analysis in the lab. 
  • Explain more precisely a result by using  scientific vocabulary

 

mercredi 15 janvier 2014

FORENSICS

FORENSICS

website : centre des sciences de Montréal
another website : CSI
dictionnary: wordreference

1) Fill this table.

the 5 evidences on this crime scene
(write the words in English and in the phonetic alphabet)
The relevant techniques  to collect the clues on the crime scene
(write the words in English and in the phonetic alphabet)
 In which lab the clues are analysed
(write the words in English and in the phonetic alphabet)



a blood stain
/blʌd steɪn/
Photography ;
/fəˈtɒgrəfi/
measurements  and 
/ˈmeʒəmənts/
diagrams ; 
 /ˈdaɪəgræm/
polilight ;
/ˈpɒlɪlaɪt/
 taking samples .
/ˈteɪkɪŋˈsɑːmpls/
Genetics laboratary
 /dʒɪˈnetɪks ləˈbɒrətəri/
a fingerprint
 /ˈfɪŋgəprɪnt/
Photography ;
measurements  and diagrams ; polilight ; 
taking samples ; 
revealing prints.
Fingersprints laboratry

traces of accelerants
/treɪsiz ɒv  ækˈselər
ɒnt]
Photography ; 
measurements  and diagrams ; taking samples.
Chemestry laboratry
 /ˈkemɪstrɪ ləˈbɒrətəri/
a bullet
/ˈbʊlɪt/
Photography ;
measurements  and diagrams ; taking samples .
Ballistics laboratry
 /bəˈlɪstɪks ləˈbɒrətəri/
textile fibers
 /ˈtekstaɪl  ˈfaɪbəʳs/
Photography ; 
measurements  and diagrams ; polilight ;
 taking samples .
Chemistry laboratry

2) Find the appliances used in these labs (write the words in English and in the phonetic alphabet)
                          In a genetics laboratory;
                          In a chemistry laboratory;
                          In a fingerprint laboratory;.
                          In a ballistics laboratory.



In the genetic lab, you need:

-      a micropipette   /ˈmaɪkrəʊpɪˈpet/

-      a PCR.
-      an electrophoresis  /ɪˌlɛktrəʊfəˈriːsɪs/

In the chemistry laboratory, you need
-      a chromatograph    /ˌkrəʊməˈtɒɡrəfɪ/
-      A mass spectrometer  /mæs spɛkˈtrɒmɪtə/

In a fingersprints laboratory, you need
-      powders  /ˈpaʊdə/
-      a computer /kəmˈpjuːtə/ ( a data base). /ˈdeɪtə beɪs/

In a ballistics laboratory, you need:
-      a water tank.
-      an Ibis hub /hʌb/. (Integrated ballistic identification System).

 
 3) Write a short explanation of what scientists do in genetics and chemistry laboratories (computers with an even number) or in  fingerprint and  ballistics laboratories (computers with an odd number).




In the genetic lab, a scientist analyzes samples like blood, saliva, hair… He/she uses a micropipette to collect very little quantities of material which contain DNA. Then the DNA is purified, and the quantity of DNA in increased with a PCR.
Finally, he/she puts some DNA on a gelatinous material in order to be analyzed with an electrophoresis. In this appliance, an electric current goes through the gelatinous material and allows the separation of DNA chemicals. The result is a DNA footprint  which is unique for each of us.


 a DNA footprint


In the chemistry laboratory.
The samples which are analyzed in a chemistry lab are alcohol, drugs, poison, dyes, explosives or other substances collected on the crime scene.
Liquid substances are analyzed with a chromatograph. The liquid is collected with a micropipette and diluted.
Then it’s injected into the chromatograph. The molecules which compose the liquid are separated according to their weight.
The result of analysis is a graph. The order of arrival represents their chemical configuration.  The height of the peaks represents how much there is of this molecule in the sample.

 
the result of a chromatograph

A mass spectrometer 
This appliance is used for solid or liquid samples. Chemicals are bombarded by electrons so chemicals are broken into tiny molecules. The mass of each molecule is measured.
The result is a graph on which all the masses of each molecule are represented. And this graph enables to indentify the chemical.



the result of a mass spectrometer

In a fingerprints laboratory, the scientist uses  powders to reveal fingerprints. The powder that is used depends on the texture, nature and the color of the background. The revealed fingerprint is photographed next to a scale
Then, the scientist uses a computer to compare the fingerprints with other prints on the data base.

 
a fingerprint comparison on a data base


a fingerprint comparison on a data base


In a ballistics laboratory, the scientist fires a shot in a water tank. Then he/she collects it at the bottom of the tank. (The water slows and stops the bullet which can be collected intact.)
Then he/she uses an Ibis hub (Integrated ballistic identification System). It takes photographs of the markings on the bullet and the cartridge case. And then it allows the comparison of these photographs with the ones on the data base.



a cartridge comparison on a data base


a cartridge comparison on a data base


a bullet comparison on a data base