Electricity, Atoms, Communication, and Ecology
Electricity and Atoms
Kilowatt-hour (kWh): Energy supplied to a circuit consuming 1 kilowatt of power for 1 hour.
Batteries: All batteries have a specific place, weight, and occupy space.
Molecule: The smallest particle of a substance that retains the chemical properties of that substance.
Simple Body or Element: Those whose molecules are made up of atoms of the same class (e.g., copper, nickel).
Compound Bodies: Formed by atoms that combine in different proportions (e.g., water, common salt).
Components of the Atom:
- Nucleus: Contains protons (positive charge) and neutrons (no charge).
- Orbit: Contains electrons (negative charge).
Centrifugal Force: Tends to move the electron out of orbit due to its spin.
Centripetal Force: Keeps electrons attracted to the nucleus due to the attraction between protons and electrons.
Nuclear Fusion: The joining of two or more different simple atomic nuclei.
Nuclear Fission or Division: The core is broken by bombarding it with neutrons.
Electric Field: The area surrounding a charge where electric actions of attraction or repulsion manifest. It is represented by lines of force.
Ionization: An atom gains or loses electrons.
- Negative Ion or Anion: Atom with an excess of electrons.
- Positive Ion or Cation: Atom with a defect of electrons.
Diamagnetic: Gold.
Telecommunications
1876: Graham Bell invented the telephone for communication via cable.
Telecommunication: An individual conveying information to another via wire, radio, etc.
- Telegraph: Uses electromagnetic waves.
- Telephony: Public service of alphanumeric and graphic transmission that does not require transcription.
Miriametric Waves: Very low-frequency wave propagation on land for long-distance radio links (0.01 to 0.03 MHz).
SHF (Super High Frequency): Super high-frequency waves used for radio links and radar (also called millimeter waves).
Grid: A set of radio link stations, usually connected to each other, using a single channel.
Network: One or more grids.
Radiotelephone of the Civil Guard: Provincial networks.
Communication Equipment: Portable (handheld radio), fixed, and mobile.
Antennas: Radiate and receive waves.
Radio Communication Modes
- Simplex Communication: You cannot talk simultaneously.
- Half-Duplex: Uses repeaters, and you cannot speak simultaneously.
QTH (Q Code): Frequency Modulation.
Frequency Modulation: Variation of the frequency of the carrier wave at the rate of variation of the frequency and amplitude of the modulating signal.
Phase Modulation: Variation of the phase of the carrier wave at the rate of the amplitude and frequency of the modulating signal.
Amplitude Modulation: Variation of the amplitude of the carrier wave in function of the modulating wave. It does *not* generate sidebands.
Sidebands: Modulation in communication generates new frequencies.
Radio Equipment
Microphone: Converts variations in voice into variations in current of the modulating wave.
Modulator: A device that produces the modulation of the carrier wave by the modulator.
Sensitivity: What the receiver receives, in decibels or microvolts.
Selectivity: Determines how far the receiver is capable of distinguishing the desired signal from other different signals.
Wave Properties
Period: The time a wave needs to travel a distance equal to one wavelength.
Scattering: Ambient humidity and large temperature differences scatter waves.
Diffraction: Energy propagates near solid objects, and waves that cannot pass through are diffracted.
Gain: The number of times the electromagnetic field produced by an antenna in the most favorable direction is greater than that produced by another antenna taken as a model.
Polarization: The direction of the electric field of the generated electromagnetic wave.
Space Wave: Radio frequency waves that do not spread and return to the generator.
Ecology
Lamarck’s Ecology: The need creates the organ; species evolve because characteristics are inherited.
Darwin: Only the individual that adapts to the environment evolves and survives.
Environment: Set of things in a habitat, aquatic or terrestrial.
Factors:
- Abiotic (or Physical): Soil, temperature, etc.
- Biotic (or Biological): Population, community, or biocenosis.
Ecosystem: Biocenosis in a biotype.
5 Kingdoms of Living Things: Plants, animals, fungi, protoctists, moneras.
Types of Ecosystems:
- Aquatic: Continental shelf and abyssal zones; living organisms include benthos, plankton (drifting), and nekton.
- Terrestrial: Polar, tundra, temperate.