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F

Fluid shift in the human body

(Last edited: Monday, 5 June 2023, 2:00 PM)



Image Source:

S, M. (2023, June 01). Illustration of fluid distribution. self. self-made

Short Definition:

The fluid shift in the body is an adaption to the reduced gravitation force in space. This results in a shift of the body fluids from the lower body to the upper body.

Detailed Definition:

When a human body is placed on the earth surface, it has a hydrostatic (gravitational) blood pressure gradient and every body region has a different arterial pressure.

In the reduced gravity of space, the hydrostatic pressure in the arteries and veins is altered to a homogeneous arterial pressure in all regions (which is the original arterial pressure of the hearth), which results in the shifted fluid distribution through the body.

The human body reduces the volume of the total fluid and after the space resident, the fluid is shifted because of the returned gravity force.

This phenomenon can cause several issues like cardiac arrhytmia, muscular athropy and visual problems (because the globe is flattened, the blood flow is changed slightly and the diamteter of the optical nerve can increase).


Etymology:
fluid - Latin fluidus ("fluid, flowing, moist")
shift - Proto-Germanic skiftan (" to divide, change, seperate")

Sample sentence(s):

A medical effect of a space flight may be a fluid shift.

Nasa is studying the effect of the fluid shift and how it affects changes in vision.

Translation:

French:

déplacement du fluide

German:

Flüssigkeitsverschiebung 

Polish:

Przemieszczenie płynu

Swedish:

vätskeförskjutning


Links to Videos/Articles:

https://www.nasa.gov/content/fluid-shifts-study-advances-journey-to-mars

https://ntrs.nasa.gov/citations/20150001888



Frequency

(Last edited: Friday, 28 April 2023, 6:09 PM)


Image Source:



Short Definition:

A frequency (f) is a physical variable which measures how often a event is repeated in a defined period of time.  

The SI-unit is Hertz (hz) or s^-1.  

A common scenario in which the frequency is used, is in a wave, in which it can be calculated by measuring the Period T (the time it takes to complete one cycle) and using the equation: f = 1/T 


Detailed Definition:
Another equation by which the frequency can be calculated, is the following with \( \lambda = \) wavelength and v= phase velocity (if the wave is detected in a vacuum, the following applies: v=c)
\( f = v/ \lambda \).

There exist two special types of frequency, the angular frequency and the spatial frequency, which will be explained in the following:
The angular frequency (ω) describes how fast a vibration / wave is occurring by measuring the overstepped phase angle of the vibration / wave in a defined time period. This frequency can be calculated in the already introduced frequency f by using the following equation:
\( \omega = 2 \pi f = 2 \pi /T \).

The spatial frequency (ξ) measures how often sinusoidal components (components of a sinusoidal wave) of a structure repeat per unit of distance, which can be calculated by using the following equation:
\( \xi = 1/ \lambda = f/v \).

Etymology:
frequency - Latin frequentia (" an assembling in great numbers, a crowding; crowd, multitude, thong")

Sample Sentence(s):
The frequency can be identified by calculating the inverse of the period T.
The frequency is a variable which can characterize a wave.

Translations:
French: Fréquence

German: Frequenz


Polish: Częstotliwość

Swedish: Frekvens


Links to Videos/Articles:
https://www.britannica.com/science/frequency-physics
https://www.youtube.com/watch?v=6WIDhLeryWM
https://www.physicsclassroom.com/class/waves/Lesson-2/Frequency-and-Period-of-a-Wave