5. Comparison of the quantum energy from a microwave oven with the thermal energy characteristic of protein denaturation:
Protein denaturation temperature t = 45 [4]:
TD = 273 + 45 = 318 К
Protein denaturation energy according to the formula (2):
ED
= k
= 1,38
= 4,388
10-21
J
The radiation frequency of the microwave oven is 2,45 GHz [5], hence the quantum energy of the microwave oven according to the formula (1):
EМ/O = h fМ/O = 6,626 10-34 2,45 109 = 1,623 10-24 J
We conclude that the energy of protein denaturation in 4,388 10-21/1,623 10-24 = 2704 times higher than the quantum energy of a microwave oven.
Analyzing the results obtained, we conclude that microwave radiation harms a person in the case when there are quite a lot of microwave radiation quanta, while heating the human body. Since we determined earlier, protein denaturation occurs at a temperature of 45 , that is, any heating of the human body negatively affects it. And, comparing the obtained value of the quantum energy of microwave radiation with the values of the energy of chemical bonding of atoms in a water molecule and the binding energy of clusters in water, we conclude that the energy of the quantum of microwave radiation (both at the 5G frequency and at the GSM frequency) is much less than these energies, and, accordingly, the quantum of microwave radiation cannot be violated chemical bonds.
Answer:
1. Quantum energy of microwave radiation:
EGSM = 5,781 10-24 J
E5G = 2,286 10-23 J
2. The energy of thermal vibrations of molecules:
ET = 4,347 10-21 J
This energy is 752 times more energy at the GSM frequency and 190 times more energy at the 5G frequency.
3. Water heating temperature necessary for the destruction of its cluster structure:
T = 2786 K
Binding energy of clusters in water:
EH20 = 0,24 eV = 3,845 10-20 J
The binding energy of clusters in water is 6651 times more energy at GSM frequency and 1682 times more energy at 5G frequency.
4. The energy of the chemical bond of atoms in a water molecule:
Echem = 4,8 eV = 7,69 10-19 J
The energy of chemical bonding of atoms in a water molecule in
133022 times more energy of the GSM standard and in 33640 times more energy of the 5G standard.
5. Protein denaturation energy according:
ED = 4,388 10-21 J
Microwave oven quantum energy:
EМ/O = 1,623 10-24 J
The energy of protein denaturation in 2704 times higher than the quantum energy of a microwave oven.
2 балл
TASK №2
2. What is the power density of microwave radiation considered acceptable in everyday life and at work according to the standards of the Russian Federation? According to international standards?
2.1 Evaluate how your body temperature will increase at home and at work at a power density level equal to 56% of the maximum allowable. What role does heat loss play in this process?
2.2 Estimate how many quanta of microwave radiation
will be required for such heating.
Here are the data from the Sanitary rules and norms 2.2.4/2.1.8.055-96 [6], and also we will enter into the table the values of the permissible power density of microwave radiation according to international standards [7]:
Таблица 1
Standard\Where |
In everyday life |
In production |
Standards of the Russian Federation |
10
|
200 W/cm2 |
International standard |
1 mW/cm2 |
10 mW/cm2 |
W/cm2
Given:
Body mass:
m = 63 kg
Height:
h = 187 cm = 1,87 m
Exposure time [8]:
t1 = 24 h = 86400 s – in everyday life
t2 = 8 h = 28800 s – in production
Solving:
Let's calculate the surface area of the body using the Mosteller formula [9]:
S =
(3)
where m – body mass; h – height.
Thus, according to formula (3) we get:
S =
=
= 1,81 m2
= 18100 cm2
Assessment of changes in body temperature in everyday life:
Maximum radiation power density in everyday life:
Pmax = 10 W/cm2
Power density level equal to 56% of the maximum:
Preal = 0,56 10 10-6 = 5,6 W/cm2
Permissible exposure power:
Pperm = Preal S = 5,6 10-6 18100 = 0,1014 W
A formula showing the change in the energy of the human body from exposure to microwave radiation:
(4)
where P – power; t – time.
Change in body heat from exposure to microwave exposure:
Qel = Pperm t1 = 0,l014 86400 = 8757,50 J
A formula showing the change in the energy of the human body from heating:
(5)
where
m – mass; c - specific heat capacity;
- temperature change.
Specific heat capacity of a human [10]:
c = 3450
So, according to formula (5), the change in body temperature is equal to:
=
(6)
Then, we get:
Assessment of changes in body temperature in production:
Maximum radiation power density in production:
Pmax = 200 W/cm2
Power density level equal to 56% of the maximum:
Preal = 0,56 200 10-6 = 112 W/cm2
Permissible exposure power:
Pperm = Preal S = 112 10-6 18100 = 2,027 W
Change in body heat from exposure to microwave exposure:
Qp = Preal t2 = 2,027 28800 = 58383,36 J
The change in body temperature in production according to the formula (6) is equal to:
That is, the change in body temperature at work is 0,269/0,0403 = 7 times greater than the change in body temperature in everyday life.
And also, we can say that the heat loss in this process is used to cool the body.