All language subtitles for 15 ElectronSpinResonanceESRdatingmethod

this video is just to show

that a numerical age is just a tip of the iceberg

and an age is actually the result

of a long and complex analytical procedure

so we are going to show you here

how we date a sample with the

is our method

the goal of this procedure

is to try to estimate the radiation

those absorbed by the NML layer

during the jurgical time

so since the death of the organism

a few keys here to understand uh

what I'm going to to tell um

to mention later on

is that ESR stands for electron spin resonance

which is a spectoscopic analytical technique

that looks at prominitic properties of materials

so first we're going to show you uh

the stand up procedure

uh in yesterdayting of facilities

first we try to cut a piece of the tooth

and then we extract the different dental tissues

the tooth is made by several dental tissues

the enamel but they're so dentine

and sometimes just cement

so we need to extract them

and then we need to clean the enamel layer

on both sides using a dentist drill

we measure the thickness of the layer

before and after cleaning

once this is done

we powder the enamel

and we save it below two hundred uh

micrometers

so at the end of the supper preparation

we have each dental tissue

separated in a different veil

and the enamel powder

so the enamel powder is divided in various liquids

which are subsempers of the same weight

the samples are carefully weighed in small tubes

before irradiation

each liquid is going to be irradiated at

increasing those

the idea is to understand the behavior

of the supper with the irridation

so after the irredation

the liquids are carefully weighed in quartz tubes

for ESR measurements

each tube is placed in a resonator

as you can see here

this is this small metal box that is located between uh

the two magnets

so a microwave is produced by a bridge

and sent to the resonator

while the magnets produce magnetic field

for each tube

we recalled an ESR signal

this is the radiation induced ESR signal

that is measured for one tube

the intensity of the signal is directly dependent

on the dose that has been absorbed by the sample

however there is also a more advanced procedure

that has been specifically designed

to minimize the damage caused to the teeth

this is essential

when we work on highly valuable samples

like human facilities

you can see here an example on this fossil Mandeville

where we took a piece of enamel from this tooth

that we analysed with ESR and uranium series

and then we glued it back to the tooth

in its original position

there is no visible damage

so the procedure here is slightly different

compared with the standout approach

once we receive the tooth

we take a few picture of it

and then extract a piece of enamel

we then again must clean the enamel

in order to remove any kind of contamination from

the adjacent dental tissues

once we have a piece of enamel

we measure its thickness

then we must prepare a simple holder for the ESM

measurements

so we use a tefral holder

in which we melt a piece of perfume

we leave it in the oven for a few minutes

in order to slightly melt it

and once the perfume is cooler

it becomes harder and saves the shape of the fragment

the objective of this procedure is to make sure

that the fragment will be systematically measured

in the exact same position

then the sample is fixed at the bottom of a quad tube

and measure

the main difference here

is that we have only one fragment

so one adequate

which means that we need to successively measure

the fragment and then irradiate it

this is a single adequate procedure

so with the animal powder

we use the multiplayer liquidity

if those method

which consists of dividing the powder in

by use sub samples that are going to be irrigated

increasing those values

this is impossible with anemic fragment

so we use the single adequate procedure

which consists of successively measuring with the s R

and irridating the same fragment