SORA

1
SORA

• CLASSES IV Sez. A-B
• TEACHERS
• ANNARITA SBARDELLA
• EMILIANA MANCINI
• VINCENZO RECCHIA

Power Point Presentation realized by

Lorenzo Corsetti (Class
VA) Cristiano Diamanti (Class VA) Francesco
DOrazio (Class VA)
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LICEO SCIENTIFICO STATALE "LEONARDO DA VINCI"
SORA ITALY COMENIUS 1.3 ENCOHAN - ENERGY IN
THE CONSUMERS HANDS 2005 - 2008
CLASSES IV Sez. A-B
TEACHERS ANNARITA SBARDELLA EMILIANA
MANCINI VINCENZO RECCHIA
3
LICEO SCIENTIFICO STATALE "LEONARDO DA VINCI"
SORA ITALY COMENIUS 1.3 ENCOHAN - ENERGY IN
THE CONSUMERS HANDS 2005 - 2008
ENCOHAN PROJECT MEETING IN HUNGHERY (6th
November / 11th November 2006)
Teachers Emiliana Mancini
Vincenzo Recchia


ENCOHAN PROJECT MEETING IN POLAND
(25th March / 1st April 2007)
Teachers Annarita Sbardella (Coordinator)
Vincenzo Recchia
Students Francesca Fornari (Class
IVA)
Martina Liburdi (Class IVA)
Luca Lombardi
(Class IVA)
Luigi Recchia (Class IVA)
Chiara Iafrate
(Class IVB)
Alessia Pantano (Class IVB)
Ilaria Urbani
(Class IVB)
Silvia Venditti (Class
IVB)
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DRINKING BIRD

• Drinking birds are thermodinamically powered toy
  heat engines that mimick the motions of a bird
  drinking from a fountain or other water source.
  They are also known as happy, dippy, dipping,
  tippy, tipping, sippy, sipping, dip-dip or
  dunking birds.
• Construction and materials
• A drinking bird consists of two glass bulbs,
  joined by a tube (the bird's neck). The tube
  extends nearly all the way into the bottom bulb
  but does not extend into the top. The space
  inside is typically filled with coloured
  dichloromethane(also known as methylene
  chloride).
• Air is removed from the apparatus, so the space
  inside the body is filled by dichloromethane
  vapour. The upper bulb has a "beak" attached,
  which along with the head, is covered in a felt
  like material. The bird is typically decorated
  with paper eyes, a blue top hat (plastic) and a
  single green tail feather. The whole setup is
  pivoted on a variable point on the neck.
• The drinking bird illustrates the conversion of
  thermal energy into mechanical energy. The head
  of the bird is coated with a fuzzy material, and
  is initially soaked in water so that it will
  begin to cool by evaporation.

Drinking birds are thermodinamically powered toy
heat engines that mimick the motions of a bird
drinking from a fountain or other water source.
They are also known as happy, dippy, dipping,
tippy, tipping, sippy, sipping, dip-dip or
dunking birds. Construction and materials A
drinking bird consists of two glass bulbs, joined
by a tube (the bird's neck). The tube extends
nearly all the way into the bottom bulb but does
not extend into the top. The space inside is
typically filled with coloured dichloromethane(als
o known as methylene chloride). Air is removed
from the apparatus, so the space inside the body
is filled by dichloromethane vapour. The upper
bulb has a "beak" attached, which along with the
head, is covered in a felt like material. The
bird is typically decorated with paper eyes, a
blue top hat (plastic) and a single green tail
feather. The whole setup is pivoted on a variable
point on the neck. The drinking bird illustrates
the conversion of thermal energy into mechanical
energy. The head of the bird is coated with a
fuzzy material, and is initially soaked in water
so that it will begin to cool by evaporation.
5
DRINKING BIRD

• This provides the temperature difference
  from head to tail necessary to run the heat
  engine. As the head cools, the colored fluid is
  observed to rise up from the bottom of the bird
  through the neck, gradually shifting the center
  of gravity of the bird toward its head. The bird
  bends at the hips and dips its bill into a glass
  of water (thus keeping the head wet and cooler
  than the tail). As the fluid continues to rise
  into the head, the fluid level in the bottom of
  the bird eventually drops below the end of the
  connecting tube. This allows vapor to be pulled
  up through the neck to equilibrate the pressure.
  The fluid runs back down into the bottom of the
  bird, the bird stands up again, and the cycle
  repeats indefinitely.
• The drinking bird is basically a heat engine
  that exploits a temperature differential to
  convert heat energy to kinetic energy and perform
  mechanical work. Like all heat engines, the
  drinking bird works through a thermodynamic
  cycle. The initial state of the system is a bird
  with a wet head oriented vertically with an
  initial oscillation on its pivot.

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DRINKING BIRD

• The cycle operates as follows
• The water evaporates from the head.
• Evaporation lowers the temperature of the glass
  head.
• The temperature drop causes some of the
  dichloromethane vapor in the head to condense.
• The lower temperature and condensation together
  cause the pressure to drop in the head (ideal gas
  law).
• The pressure differential between the head and
  base causes the liquid to be pushed up from the
  base.
• As liquid flows into the head, the bird becomes
  top heavy and tips over during its oscillations.
• When the bird tips over, the bottom end of the
  neck tube rises above the surface of the liquid.
• A bubble of vapor rises up the tube through this
  gap, displacing liquid as it goes
• Liquid flows back to the bottom bulb, and vapor
  pressure equalizes between the top and bottom
  bulbs
• The weight of the liquid in the bottom bulb
  restores the bird to its vertical position.

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DRINKING BIRD

• If a glass of water is placed so that the beak
  dips into it on its descent, the bird will
  continue to absorb water and the cycle will
  continue as long as there is enough water in the
  glass to keep the head wet. However, the bird
  will continue to dip even without a source of
  water, as long as the head is wet, or as long as
  a temperature differential is maintained between
  the head and body. This differential can be
  generated without evaporative cooling in the head
  -- for instance, a heat source directed at the
  bottom bulb will create a pressure differential
  between top and bottom that will drive the
  engine. The ultimate source of energy is heat in
  the surrounding environment -- the toy is not a
  perpetual motion machine.

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THE PHISICS AROUND

• 1) Heat engine
• A heat engine is a physical or theoretical device
  that converts thermal energy to mechanical
  output. The mechanical output is called work, and
  the thermal energy input is called heat. Heat
  engines typically run on a specific thermodynamic
  cycle. Heat engines are often named after the
  thermodynamic cycle they are modeled by. They
  often pick up alternate names, such as
  gasoline/petrol, turbine, or steam engines. Heat
  engines can generate heat inside the engine
  itself or it can absorb heat from an external
  source. Heat engines can be open to the
  atmospheric air or sealed and closed off to the
  outside (Open or closed cycle).
• In engineering and thermodynamics, a heat engine
  performs the conversion of heat energy to
  mechanical work by exploiting the temperature
  gradient between a hot "source" and a cold
  "sink". Heat is transferred from the source,
  through the "working body" of the engine, to the
  sink, and in this process some of the heat is
  converted into work by exploiting the properties
  of a working substance (usually a gas or liquid).

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THE PHISICS AROUND
Figure 1 Heat engine diagram
Heat engines are often confused with the cycles
they attempt to mimic. Typically when describing
the physical device the term 'engine' is used.
When describing the model the term 'cycle' is
used. In thermodinamics, heat engines are often
modeled using a standard engineering model such
as the Otto cycle (4-stroke/2-stroke). Actual
data from an operating engine, one is called a
indicator diagram, is used to refine the model.
All modern implementations of heat engines do not
exactly match the thermodynamic cycle they are
modeled by. One could say that the thermodynamic
cycle is an ideal case of the mechanical engine.
One could equally say that the model doesn't
quite perfectly match the mechanical engine.
However, much benefit is gained from the
simplified models, and ideal cases they may
represent.
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THE PHISICS AROUND

• In general terms, the larger the difference
  in temperature between the hot source and the
  cold sink, the larger is the potential thermal
  efficiency of the cycle. On Earth, the cold side
  of any heat engine is limited to close to the
  ambient temperature of the environment, or not
  much lower than 300 kelvins, so most efforts to
  improve the thermodynamic efficiencies of various
  heat engines focus on increasing the temperature
  of the source, within material limits.
• The efficiency of various heat engines
  proposed or used today ranges from 3 percent (97
  percent waste heat) for the OTEC ocean power
  proposal through 25 percent for most automotive
  engines, to 35 percent for a supercritical coal
  plant, to about 60 percent for a steam-cooled
  combined cycle gas turbine. All of these
  processes gain their efficiency (or lack thereof)
  due to the temperature drop across them.

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THE PHISICS AROUND

• OTEC uses the temperature difference of ocean
  water on the surface and ocean water from the
  depths, a small difference of perhaps 25 degrees
  Celsius, and so the efficiency must be low. The
  combined cycle gas turbines use natural-gas fired
  burners to heat air to near 1530 degrees Celsius,
  a difference of a large 1500 degrees Celsius, and
  so the efficiency can be large when the
  steam-cooling cycle is added in

Figure 1 Heat engine diagram
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THE PHISICS AROUND

• Examples of everyday heat engines include the
  steam engine, the diesel engine, and the gasoline
  (petrol) enginein an automobile. A common toy
  that is also a heat engine is a drinking bird.
  All of these familiar heat engines are powered by
  the expansion of heated gases. The general
  surroundings are the heat sink, providing
  relatively cool gases which, when heated, expand
  rapidly to drive the mechanical motion of the
  engine.
• It is important to note that although some cycles
  have a typical combustion location (internal
  external), they often can be implemented as the
  other combustion cycle. For example, John
  Ericsson developed an external heated engine
  running on a cycle very much like the earlier
  Diesel cycle. In addition, the externally heated
  engines can often be implemented in open or
  closed cycles.
• What this boils down to is there are
  thermodynamic cycles and a large number of ways
  of implementing them with mechanical devices
  called engines.

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THE PHISICS AROUND

• 2) Evaporation and condensation
• EVAPORATION

Evaporation is the process whereby atoms or
molecules in a liquid state gain sufficient
energy to enter the gaseous state (the equivalent
process in solids is known as sublimation). It is
the opposite process of condensation. Evaporation
is exclusively a surface phenomena and should not
be confused with boiling. Most notably, for a
liquid to boil, its vapor pressure must equal the
ambient pressure, whereas for evaporation to
occur, this is not the case. The vapor pressure
of a liquid is the pressure exerted by its vapor
when the liquid and vapor are in dynamic
equilibrium.
Water condenses into visible droplets after
evaporating from a cup of hot tea
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THE PHISICS AROUND

• In chemistry and physics, vapor pressure is
  the pressure of a vapor in equilibrium with its
  non-vapor phases. All solids and liquids have a
  tendency to evaporate to a gaseous form, and all
  gases have a tendency to condense back. At any
  given temperature, for a particular substance,
  there is a partial pressure at which the gas of
  that substance is in dynamic equilibrium with its
  liquid or solid forms. This is the vapor pressure
  of that substance at that temperature. In
  meteorology, the term vapor pressure is used to
  mean the partial pressure of water vapor in the
  atmosphere, even if it is not equilibrium, and
  the equilibrium vapor pressure is specified as
  such. Meteorologists also use the term saturation
  vapor pressure to refer to the equilibrium vapor
  pressure of water or brine above a flat surface,
  to distinguish it from equilibrium vapor pressure
  which takes into account the shape and size of
  water droplets and particulates in the
  atmosphere.

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THE PHISICS AROUND

• Vapor pressure is an indication of a liquid's
  evaporation rate. It relates to the tendency of
  molecules and atoms to escape from a liquid or a
  solid. A substance with a high vapor pressure at
  normal temperatures is often referred to as
  volatile. The higher the vapor pressure of a
  material at a given temperature, the lower the
  boiling point.
• The vapor pressure of any substance increases
  non-linearly with temperature according to the
  Clausius-Clapeyron relation. The boiling point of
  a liquid is the temperature where the vapor
  pressure equals the ambient atmospheric pressure.
  At the boiling temperature, the vapor pressure
  becomes sufficient to overcome atmospheric
  pressure and lift the liquid to form bubbles
  inside the bulk of the substance. Evaporation is
  a critical component of the water cycle, which is
  responsible for clouds and rain. Solar energy
  drives evaporation of water from oceans, lakes,
  moisture in the soil, and other sources of water.
  In hydrology, evaporation and transpiration
  (which involves evaporation within plant stomata)
  are collectively termed evapotranspiration.

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THE PHISICS AROUND

• CONDENSATION

Condensation is the change in matter of a
substance to a denser phase, such as a gas (or
vapor) to a liquid. Condensation commonly occurs
when a vapor is cooled to a liquid, but can also
occur if a vapor is compressed (i.e., pressure on
it increased) into a liquid, or undergoes a
combination of cooling and compression. Liquid
which has been condensed from a vapor is called
condensate. A device or unit used to condense
vapors into liquid is called a condenser.
Condensers are typically coolers or heat
exchangers which are used for various purposes,
have various designs, and come in many sizes
ranging from rather small (hand-held) to very
large. Condensation of vapor of liquid is the
opposite of evaporation or boiling and is an
exothermic process, meaning it releases heat. The
water seen on the outside of a cold glass on a
hot day is condensation.
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THE PHISICS AROUND

• CONDENSATION OF WATER IN NATURE

Water vapor from air which naturally condenses on
cold surfaces into liquid water is called dew.
Water vapor will only condense onto another
surface when that surface is cooler than the
temperature of the water vapor, or when the water
vapor equilibrium in air, i. e. saturation
humidity, has been exceeded. When water vapor
condenses onto a surface, a net warming occurs on
that surface.
Dew on a spider web
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THE PHISICS AROUND

• The water molecule brings a parcel of heat with
  it. In turn, the temperature of the atmosphere
  drops very slightly. In the atmosphere,
  condensation of water vapour is what produces
  clouds. The dew point of an air parcel is the
  temperature to which it must cool before
  condensation in the air begins to form.
• Also, a net condensation of water vapor occurs on
  surfaces when the temperature of the surface is
  at or below the dew point temperature of the
  atmosphere. Deposition is a type of condensation.
  Frost and snow are examples of deposition (or
  sublimation). Deposition is the direct formation
  of ice from water vapor.

Condensation on a cold bottle of water
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THE PHISICS AROUND

• APPLICATIONS OF CONDENSATION

Because condensation is a naturally occurring
phenomenon, it can often be used to generate
water in large quantities for human use. In fact,
there are many structures that are made solely
for the purpose of collecting water from
condensation, such as fog fences, air wells and
dew ponds. Such systems can often be used to
retain soil moisture in areas where active
desertification is occurring. In fact, certain
organizations use education about water
condensers in efforts to effectively aid such
areas.
CONDENSATION IN BUILDINGS
Condensation is the most common form of dampness
encountered in buildings. In buildings the
internal air can have a high level of relative
humidity due to the activity of the occupants
(e.g. cooking, drying clothes, breathing etc...).
When this air comes into contact with cold
surfaces such as windows and cold walls it can
condense, causing dampness.
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THE PHISICS AROUND

• 3) Ideal gas law

The ideal gas law is the equation of state of a
hypothetical ideal gas, first stated by Benoît
Paul Émile Clapeyron in 1834.
The state of an amount of gas is determined by
its pressure, volume, and temperature according
to the equation
where
is the pressure PAL
is the volume m
3
is the amount of substance of gas mol,
is the gas constant 8.3143 m3PaK-1mol-1, and
is the temperature in kelvins K.
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THE PHISICS AROUND

• The ideal gas constant (R) is dependent on what
  units are used in the formula. The value given
  above, 8.314472, is for the SI units of
  pascal-cubic meters per mole-kelvin. Another
  value for R is 0.082057 L atm mol-1 K-1)
• The ideal gas law is the most accurate for
  monatomic gases and is favored at high
  temperatures and low pressures. It does not
  factor in the size of each gas molecule or the
  effects of intermolecular attraction. The more
  accurate Van der Waals equation takes these into
  consideration.

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THE PHISICS AROUND

• Alternate forms
• Considering that the number of moles (n) could
  also be given in mass, sometimes you may wish to
  use an alternate form of the ideal gas law. This
  is particularly useful when asked for the ideal
  gas law approximation of a known gas. Consider
  that the number of moles (n) is equal to the mass
  (m) divided by the molar mass (M), such that

Then, replacing n gives in statistical
mechanics, and is often derived from first
principles
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THE PHISICS AROUND

• Here, kb is Boltzmann's constant, and N is
  the actual number of molecules, in contrast to
  the other formulation, which uses n, the number
  of moles. This relation implies that Nkb nR,
  and the consistency of this result with
  experiment is a good check on the principles of
  statistical mechanics.
• From here we can notice that for an average
  particle mass of µ times the atomic mass of
  Hydrogen,

and since ? m / V, we find that the ideal gas
law can be re-written as
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THE PHISICS AROUND
PROOF Empirical The ideal gas law can be proved
using Royle,Charles and Gay-Lussac
laws. Consider an amount of gas. Let its initial
state be defined as
volume v0 pressure p0 temperature t0
If this gas now undergoes an isobaric process,
its state will change
volume
pressure
temperature
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THE PHISICS AROUND
If it then undergoes an isothermal process
Where
p final pressure v final volume T final
temperature ( t')
So
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THE PHISICS AROUND

• Where

termed R, is the universal gas constant
Using this notation we get
And multiplying both sides of the equation by n
(numbers of moles)
Using the symbol V as a shorthand for nv (volume
of n moles) we get
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THE PHISICS AROUND

• Theoretical
• The ideal gas law can also be derived from first
  principles using the kinetic theory of gases, in
  which several simplifying assumptions are made,
  chief amongst which is that the molecules, or
  atoms, of the gas are point masses, possessing
  mass but no significant volume.

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LEVITRON

• The LEVITRON is formed by a top that hangs above
  a base while is spinning. The 'antigravity' force
  that repels the top from the base is magnetism.
  Both the top and the heavy slab inside the base
  box are magnetized, but oppositely. Think of the
  base magnet with its north pole pointing up, and
  the top as a magnet with its north pole pointing
  down. The principle is that two similar poles
  (e.g., two norths) repel and that two opposite
  poles attract, with forces that are stronger when
  the poles are closer. There are four magnetic
  forces on the top on its north pole, repulsion
  from the base's north and attraction from the
  base's south, and on its south pole, attraction
  from the base's north and repulsion from the
  base's south. Because of the way the forces
  depend on distance, the north-north repulsion
  dominates, and the top is magnetically repelled.
  It hangs where this upward repulsion balances the
  downward force of gravity, that is, at the point
  of equilibrium where the total force is zero. 

29
LEVITRON

• As well as providing a force on the top as a
  whole, the magnetic field of the base gives a
  torque tending to turn its axis of spin. If the
  top were not spinning, this magnetic torque would
  turn it over. Then its south pole would point
  down and the force from the base would be
  attractive - that is, in the same direction as
  gravity - and the top would fall. When the top is
  spinning, the torque acts gyroscopically and the
  axis does not overturn but rotates about the
  (nearly vertical) direction of the magnetic
  field. This rotation is called precession. With
  the LEVITRON, the axis is nearly vertical and the
  precession is visible as a shivering that gets
  more pronounces as the top slows down.
• For the top it remain suspended, equilibrium
  alone is not enough. The equilibrium must also be
  stable , so that a slight horizontal or vertical
  displacement produces a force pushing the top
  back toward the equilibrium point.

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LEVITRON

• For the LEVITRON, stability is difficult to
  achieve. It depends on the fact that as the top
  moves sideways, away from the axis of the base
  magnet, the magnetic field of the base, about
  which the top's axis precessed, deviates slightly
  from the vertical. If the top precessed about the
  exact vertical, the physics of magnetic fields
  would make the equilibrium unstable. Because the
  field is so close to vertical, the equilibrium is
  stable only in a small range of heights - between
  about 1.25 inches and 1.75 inches above the
  center of the base. (between 2.5 and 3.0 inches
  for Fascinations' new Super LEVITRON). The
  Earnshaw theorem is not violated by the behavior
  of the LEVITRON. That theorem states that no
  static arrangements of magnetic (or electric)
  charges can be stable, alone or under gravity. It
  does not apply to the LEVITRON because the magnet
  (in the top ) is spinning and so responds
  dynamically to the field from the base.

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LEVITRON

• The weight of the top and the strength of
  magnetization of the base and the top determine
  the equilibrium height where magnetism balances
  gravity. This height must lie in the stable
  range. Slight changes of temperature alter the
  magnetization of the base and the top. (as the
  temperature increases, the directions of the
  atomic magnets randomize and the field weakens).
  Unless the weight is adjusted to compensate, the
  equilibrium will move outside the stable range
  and the top will fall. Because the stable range
  is so small, this adjustment is delicate - the
  lightest washer is only about 0.3 of the weight
  of the top.
• The top spins stable in the range from about 20
  to 35 revolutions per second (rps). It is
  completely unstable above 35-40 rps and below 18
  rps. After the top is spun and levitated, it
  slows down because of air resistance. After a few
  minutes it reaches the lower stability limit (18
  rps) and falls.

32

LEVITRON

• The spin lifetime of the LEVITRON can be extended
  by placing it in a vacuum. In a few vacuum
  experiments that have been done the top fell
  after about 30 minutes. Why it does so is not
  clear perhaps the temperature changes, pushing
  the equilibrium out of the stable range perhaps
  there is some tiny residual long-term instability
  because the top is not spinning fast enough or
  perhaps vibrations of the vacuum equipment jog
  the field and gradually drive the precession axis
  away from the field direction. Levitation can be
  greatly prolonged by blowing air against an
  appropriately serrated air collar placed around
  the top's periphery so as to maintain the spin
  frequency in the stable range.

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LEVITRON

• Recently a LEVITRON top was kept rotating for
  several days in this way. But the most successful
  means to prolong the top's levitation is with
  Fascinations' new PERPETUATOR, an
  electro-magnetic pulsed device which can keep the
  top levitating for many days or even weeks. 
• In recent decades, microscopic particles have
  been studied by trapping them with magnetic
  and/or electric fields. There are several sorts
  of traps. For example, neutrons can be held in a
  magnetic field generated by a system of coils.
  Neutrons are spinning magnetic particles, so the
  analogy of such a neutron trap with the LEVITRON
  is close.

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THE PHISICS AROUND

• 1) Magnetism

35
THE PHISICS AROUND
Magnetism has been known since ancient times. The
magnetic property of lodestone (Fe3O4) was
mentioned by the Greek philosopher Thales (c. 500
BC), and the Greeks called this mineral
"Magnetic", after the province of Magnesia in
Thessaly where it was commonly found. It was also
found in the nearby province of Heraclia, which
is presumably why Socrates says that most people
called the stone "Heraclian". Apparently we have
the great dramatist Euripides to thank for not
having to pronounce the electro-heraclian field.
About 1000 AD the Chinese began to use lodestone
as a compass for finding directions on land, and
soon afterwards Muslim sailors were using
compasses to navigate at sea. Europeans began
using magnetic compasses for navigation around
1200 AD, probably bringing the idea back from the
Crusades.
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THE PHISICS AROUND
The first scientific study of magnets was
apparently by the English physician William
Gilbert in 1600, who is credited with
"discovering" that the Earth itself is a magnet.
After Gilbert, the subject languished for almost
200 years, as the attention of most scientists
turned to gravitation and working out the
consequences of Newton's great synthesis of
dynamics and astronomy. Not until 1785 was the
subject taken up again, first by the Frenchman
Charles Coulomb, then by Poisson, Oersted,
Ampere, Henry, Faraday, Weber, and Gauss,
culminating in Maxwell's classical synthesis of
electromagnetic theory in 1875. However, despite
the great achievements of these scientists, no
satisfactory understanding of the various kinds
of magnetic behavior exhibited by different
materials was achieved. Only with the advent of
quantum mechanics in the 1920's did it become
possible to give a coherent account of the main
magnetic properties of materials. It's a
surprisingly complex subject, but we can give a
broad outline of the modern explanations of
magnetic phenomena.
37
THE PHISICS AROUND

• The three main types of magnetic behavior
  exhibited by material substances are called
  diamagnetism, paramagnetism, and ferromagnetism.
  The first two can be explained in terms of the
  magnetic fields produced by the orbital motions
  of the electrons in an atom. Each electron in an
  atom can be regarded as having some "orbital"
  motion about the nucleus, and this moving charge
  represents an electric current, which sets up a
  magnetic field for the atom, as shown below.

38
THE PHISICS AROUND
Many atoms have essentially no net magnetic
dipole field, because the electrons orbit the
nucleus about different axes, so their fields
cancel out. Thus, whether or not an atom has a
net dipole field depends on the structure of the
electron shells surrounding the nucleus. In broad
terms, diamagnetism and paramagnetism are
different types of responses to an externally
applied magnetic field. Diamagnetism is a natural
consequence of Lenz's law, according to which the
electric current resulting from an applied field
will be in the direction that opposes the applied
field. . In other words, the induced current will
flow in the direction that creates a field
opposite to the applied field, as illustrated
below
39
THE PHISICS AROUND
Conservation of energy implies that a force is
required to push the magnet through the ring,
thereby setting up the flow of current (in the
opposite direction of the electron motion). Hence
there is a repulsive force between the magnet and
the conducting ring. Likewise when an atom is
subjected to an applied magnetic field, there is
a tendency for the orbital motions of the
electrons to change so as to oppose the field.
40
THE PHISICS AROUND

• As a result, the atom is repelled from any
  magnetic field. Notice that this is true
  regardless of the polarity of the applied field,
  because the induced "currents" (i.e., the induced
  changes in the orbital motions of the electrons)
  invariably act to oppose the applied field. This
  phenomenon is present in all substances to some
  degree, but it is typically extremely small, so
  it is not easily noticed. It is most evident for
  elements whose atoms have little or no net
  magnetic moment (absent an externally applied
  field). Among all the elements at ordinary room
  temperatures, bismuth has the strongest
  diamagnetism, but even for bismuth the effect is
  extremely weak, because the currents that can be
  established by the electron orbital motions are
  quite small. It's possible, however, to construct
  a perfect diamagnet using superconductivity.

41
THE PHISICS AROUND

• A superconductor is, in many respects, like a
  quantum-mechanical atom, but on a macroscopic
  scale, and it can support very large currents. In
  accord with Lenz's Law, these currents oppose any
  applied field, so it's actually possible to
  achieve stable levitation of a permanent magnet
  over a superconductor. In view of Lenz's Law, it
  might seem surprising that any material could
  actually be attracted to a magnetic field, but in
  fact there are many such substances. This is due
  to the phenomena called paramagnetism. Unlike the
  atoms of diamagnetic materials, the electrons of
  atoms in paramagnetic materials are arranged in
  such a way that there is a net magnetic dipole
  due to the orbital motions of the electrons
  around the nucleus. Thus, each atom is a small
  permanent magnet, but the poles tend to be
  oriented randomly, so a macroscopic sample of the
  substance usually has no net magnetic field.

42
THE PHISICS AROUND

• When such a substance is subjected to an external
  magnetic field, there is (as always) a small
  diamagnetic effect on the orbital motions of the
  electrons, tending to cause a repulsion (as
  explained above), but there is also a tendency
  for the individual atomic dipoles to become
  aligned with the imposed field, rather than being
  oriented randomly. This gives the substance an
  overall net magnetic dipole in the same direction
  as the applied field, so if the substance is
  located in a non-uniform magnetic field, it will
  be attracted in the direction of increasing field
  strength. This paramagnetic attraction effect is
  much stronger than the diamagnetic repulsion, so
  paramagnetism usually masks the effect of
  diamagnetism for such substances. However, even
  paramagnetism is so weak that it's often not
  noticed, because the thermal agitation of the
  atoms (at room temperature) tends to disrupt the
  alignment.

43
THE PHISICS AROUND

• The last major category of magnetic behavior is
  called ferromagnetism. This is the phenomenon
  responsible for the strong magnetic properties of
  iron, and for the existence of permanent magnets,
  i.e., macroscopic substances (such as magnetite)
  that exhibit an overall net magnetic dipole
  field, even in the absence of any externally
  applied field. Many of the early researchers in
  the science of magnetism thought this was nothing
  but a strong and persistent form of
  paramagnetism, but the strength and persistence
  of ferromagnetism show that it is the result of a
  fundamentally different mechanism, an effect that
  is absent in merely paramagnetic substances
  Whereas both diamagnetism and paramagnetism are
  essentially due to the atomic fields resulting
  from the orbital motions of the electrons about
  the nucleus, ferromagnetism is due almost
  entirely to alignment of the intrinsic spin axes
  of the individual electrons.

44
THE PHISICS AROUND

• An individual electron possesses a quantum
  property known as "spin", which is somewhat
  analogous to the spin of a macroscopic object.
  (This analogy is not exact, and can be misleading
  in some circumstances, but it's useful for
  gaining an intuitive understanding of the
  magnetic properties of materials.) According to
  this view, an electron's charge is distributed
  around its surface, and the surface is spinning
  about some axis, so there is a tiny current loop,
  setting up a magnetic field as illustrated below.

45
THE PHISICS AROUND

• The contribution of the nucleus itself to the
  magnetic field of an atom is typically negligible
  compared with that of the electrons. In most
  elements the spin axes of the electrons point in
  all different directions, so there is no
  significant net magnetic dipole. However, in
  ferromagnetic substances, the intrinsic spins of
  many of the electrons are aligned, both within
  atoms and between atoms. The key question is what
  causes all these dipoles to be aligned,
  especially in the absence of an external field.
  It can be shown that the dipole interaction
  itself is not nearly strong enough to achieve and
  maintain alignment of the electron spin axes at
  room temperatures, so some other factor must be
  at work.

46
THE PHISICS AROUND

• Quantum mechanics furnishes the explanation For
  particular arrangements of certain kinds of atoms
  in the lattice structure of certain solids, the
  inter-electron distances within atoms and between
  neighboring atoms are small enough that the wave
  functions of the electrons overlap significantly.
  As a result, there is a very strong effective
  "coupling force" between them due to their
  indistinguishability. This is called an "exchange
  interaction", and is purely a quantum-mechanical
  phenomenon. There is no classical analogy. In
  essence, quantum mechanics tells us that there is
  a propensity for the identities of neighboring
  electrons to be exchanged, and this locks the
  spin orientations of the electrons together.

47
THE PHISICS AROUND

• (This is actually true only under certain
  circumstances. It's also possible for exchange
  interactions to lock the spins of neighboring
  electrons in opposite directions, in which case
  the behavior is called anti-ferromagnetism.) In
  order for the exchange interaction to operate,
  the inter-electron distances must be just right,
  and these distances are obviously affected by the
  temperature, so there is a certain temperature,
  called the Curie temperature, above which
  ferromagnetism breaks down. Only five elements
  have electron shell structures that support
  ferromagnetism, namely, iron, cobalt, nickel,
  gadolinium, and dysprosium. In addition, many
  compounds based on these elements are also
  ferromagnetic. (One example is the compound
  Fe3O4, also called lodestone, which the ancient
  Greeks found lying around in Magnesia.) These are
  all "transition elements", with partially
  populated 3d inner electron shells.

48
THE PHISICS AROUND

• When magnetized, the spin axes of all the
  electrons in the 3d shells are aligned, not only
  for one atom, but for neighboring atoms as well.
  This gives the overall lattice of atoms a very
  strong net magnetic dipole. It's worth noting
  that this is due to the intrinsic spins of the
  individual electrons, not due to the orbital
  motions of the electrons (as is the case with
  diamagnetism and paramagnetism). Recall that, for
  paramagnetic substances, the alignment of atomic
  dipoles is maintained only as long as the
  external field is applied. As soon as the field
  is removed, the atomic dipoles tend to slip back
  into random orientations. This is because the
  ordinary dipole field is not nearly strong enough
  to resist thermal agitation at room temperatures.
  In contrast, after a ferromagnetic substance has
  been magnetized, and the externally applied field
  is removed, a significant amount of magnetization
  remains.

49
THE PHISICS AROUND

• In general, the electron spins of all the atoms
  with a suitable lattice will be locked in
  alignment, with or without an external field, but
  a real large-scale piece of a substance typically
  cannot be a single perfectly coherent lattice.
  Instead, it consists of many small regions of
  pure lattices, within which the exchange
  interaction keeps all the electron spins aligned,
  but the exchange interaction does not extend
  across the boundaries between domains. In effect,
  these boundaries are imperfections in the
  lattice. As a result, although each small domain
  is perfectly magnetized, the domains in an
  ordinary piece of iron are not aligned, so it has
  no significant net magnetic field. However, when
  subjected to an external field, there is enough
  extra impetus to trigger a chain reaction of
  alignment across the boundaries of the individual
  regions in the iron, causing the overall object
  to become a magnet.

50
THE PHISICS AROUND

• This is the phenomenon described by Socrates,
  when he explained how a Magnet has the power not
  only to attract iron, but to convey that power to
  the iron. He was describing a purely quantum
  mechanical effect, by which an applied magnetic
  field causes the intrinsic spin axes of
  individual electrons in the 3d shells of
  transition elements such as iron to become
  aligned - although he presumably wasn't thinking
  about it in those terms. When the external field
  is removed, the various regions in the iron
  object will tend to slip back to their natural
  orientations, given the imperfections in the
  lattice structure, so much of magnetism of the
  object will be lost. However, there will be
  typically have been some structural
  re-organization of the lattice (depending on the
  strength of the applied field, and the
  temperature of the iron), so that a higher
  percentage of the domains are aligned, and this
  re-structuring of the lattice persists even after
  the external field is removed.

51
THE PHISICS AROUND

• This accounts for the hysteresis effect, by which
  a piece of iron acquires some permanent magnetism
  after having been exposed to a strong field. In
  order to create a strong permanent magnet, a
  piece of ferrous material is heated to a molten
  state, and then placed in a strong magnetic field
  and allowed to cool. This creates a lattice
  structure with very few magnetic imperfections in
  the lattice, so the electron spins are naturally
  locked in alignment throughout the material. Not
  surprisingly, if a magnetized piece of iron is
  struck with a hammer, it's possible to scramble
  the domains and thereby de-magnetize the object
  In summary, the three main kinds a magnetism are
  illustrated schematically in the figures below.

52
THE PHISICS AROUND

• 2) Gyroscope
• The gyroscope is an instrument that allows to
  verify immediately that an object placed in spin
  stretches to conserve the direction of the spin
  axis. The force necessary to move the direction
  of the spin axis is as greater as the rotation
  spin speed is. This means that an object place in
  very fast spin keeps the direction of its spin
  axis costant. On this principle very
  sophisticated devices are based in the guide of
  the airplanes that make satellite navigation
  systems work. You can find them in the most
  expensive cars. Also the possibility to be in
  equilibrium on a bicycle is tied partially to the
  speed of spin of the wheels that stretch to
  maintain to horizontal their spin axis and
  therefore contrasts the tendency of the bicycle
  to falling on a side.

53
THE PHISICS AROUND
Gyroscope used in satellite navigation systems
In satellite navigation systems it is essential
to know the position of the automobile. The
gyroscope is used in this case to know the value
of the angular movement (rotations) made by
vehicle. The gyroscope installed on the
navigation system, generally settled on the back
of the automobile is a sensor of piezoelectric
angular velocity (Rate Gyro). So its a sensible
sensor to rotation angular velocity that through
integration in time gives information about the
angular movement (degrees) made by the car.
54
THE PHISICS AROUND

• Functioning
• The heart of the device is a ceramics bar line
  that flutes around his longitudinal axis. The bar
  line is suspended on two metallic axis with two
  welding points settled on the oscillation
  junctions of the bar line. If the bar line rolls,
  it originates the Coriolis force on the normal
  level to the one of oscillation, proportional to
  the angular velocity. The piezoelectric platens
  applied on the bar line are useful to vibrate the
  bar line lengthwise and to eliminate the
  vibration on the normal level, originated by
  Coriolis force. The essential tension to
  eliminate the vibration on the normal level gives
  information about the speed of the rotation of
  bar line (so the gyroscope). So the gyroscope
  generates an exit tension proportional to the
  angular velocity to which its submitted.

55
THE PHISICS AROUND

• The Artificial Horizon
• The Artificial Horizon is the pointer of order
  generally employed on the simpler airplanes.
  
  The spin
  axis is constituted by a gyroscope to three
  degrees of freedom, having vertically disposed,
  and therefore the disc place in spin in the
  horizontal plan.
  
  In agreement to gyroscope there is a line or
  a representation of the horizon, that is
  therefore always parallel to the horizon, while
  in agreement to the case of the instrument is a
  shape that represents the airplane, which can be
  rised or lowered on the horizon through an
  appropriate revolving knurl. Making the shape
  coincide with the line of the horizon when the
  airplane is on the line of flight, the assumed
  orders can be visualized around to the bank axis
  and around to its pitch.

56
THE PHISICS AROUND

• The picture shows five flight attitudes indicated
  by an artificial horizon

57
THE PHISICS AROUND

• TWO CURIOUS PHISYCAL EXPERIENCES
• Seats and gyroscopeseated over a revolving
  seat,we support a bycicle wheel,with an
  horizontal axis(the wheel has two handles)if the
  wheel is put in spin,and we tilt the axis of the
  wheel,we also begin to turn.

Suspended wheela bycicle wheel with an axis, an
extremity of which is suspended to the ceiling
trough a rope,it is kept to turning with the
horizontal axis and,after that,is released.What
does the wheel do? Contrarily at what we
think,the wheel maintains its horizontal axis
until the speed of the spin is quite high.
58
THE PHISICS AROUND

• SHORT HISTORY OF THE BICYCLE
• The origins of the bicycle are debatables.
• In 1796,a celerifero ,vehicle equipped of two
  wheels on the same vertical axis, was assembled.
• The wheels were linked by a small beam (not yet
  equipped of a seat) astride of which they moved
  thanks to the push gave from the feet .
• Some years after,the German Drais inserted two
  remarkable varyingsa saddleback to sit and a
  handle-bar to ride the mean.

59
THE PHISICS AROUND

• DRAISINA (1820)
• The celerifero,and later velocifero, was
  constituted by a wooden rigid chassis with two
  wheels on which the rider stood astride,pulling
  the mean with his feet.
  The Bavarian baron
  Carl von Drais,in 1818,modified his own
  velocifero equipping it with a handle-bar to
  direct the anterior wheel,making easier the use
  and the maneuver.
  This mean was called Draisino and it
  can be considered as a precursor of the current
  bicycles. The Draisina represented an
  enormous progress about celeriferi which,in
  fact,could not steer and, therefore, face curves.

60
THE PHISICS AROUND

• MICHAUX PENNY-FARTHING (1869)
• With the application of the stocks on the front
  wheel born the michaudine.
• The name of these velocipedi comes from French
  mechanics Piero Ernesto Michaux(father and son).

61
THE PHISICS AROUND

• DRAISINA WITH LEVERS
• TECHNICAL DESCRIPTION
• A draisina with levers,stocks and connecting
  rodsonly lever for steering-gear and brake

62
THE PHISICS AROUND

• PENNY-FARTHING LALLEMENT

TECHNICAL DESCRIPTION Pedals introduction on a
loom like draisina Hanged saddle
elastically steering and pedals to the drive
wheel elegant shape of the support crosspiece.
63
THE PHISICS AROUND

• PENNY-FARTHING ENGLISH MODEL

TECHNICAL DESCRIPTION Hanged saddle
elastically Recordable pedals Sliding block
brake on the posterior wheel.
64
THE PHISICS AROUND

• TRICYCLE MURNIGOTTI (1879)

TECHNICAL DESCRIPTION First application of the
motor to the tricycle to hydrogen engine two
cylinders.
65
THE PHISICS AROUND

• KANGOROO(1880)

Marseillaise Rousseau decided to apply two gears
with transmission to chain in order to increase
the speed, and he realized it in 1878. Later on,
in order to distinguish from the other
exemplaries, it was called Kangoroo.In order to
avoid the turn over of the runner, typical of the
bicycles with two wheels of great diameter, the
use of the chain with multiplies is introduced in
order to contain the diameter of the front wheel
and to maintain a high speed in means.
66
THE PHISICS AROUND

• MONOCYCLE (1882)

TECHNICAL DESCRIPTION Iron chassis Iron wheel
with radial and driven in beams.
67
THE PHISICS AROUND

• CADRE BI-CYCLE (1885)

TECHNICAL DESCRIPTION Front stirrups for
rest Posterior stirrups for climb in
race Humber chain Recordable pedals.
68
THE PHISICS AROUND

• BICYCLE (1893)

TECHNICAL DESCRIPTION Ice-skate brake on the
front wheel French galle chain Pneumatic
rubbers
69
THE PHISICS AROUND

• 3) The Earnshaw theorem

One of the most common questions about permanent
magnets is whether there exist a stable and
static configuration of permanent magnets that
will cause an object to be levitated
indefinitely. Obviously the levitation itself is
not a problem, because many magnets have fields
strong enough to lift their own weight.
Equilibrium is also not a problem, because there
is obviously a configuration at the boundary
between falling and rising. The problem is
stability. In order to have stability, there must
be a restorative force counter-acting any
displacement away from the equilibrium point. We
need to be careful when considering this
question, because, as discussed above, there are
several kinds of magnetic behavior exhibited by
different substances in different circumstances.
We can certainly achieve stable levitation with a
superconductor, which is really just a perfect
diamagnet.
70
THE PHISICS AROUND

• In fact, even at room temperatures, it is
  possible to use the diamagnetic property of a
  substance like bismuth to achieve (marginal)
  stability for magnetic levitation. Of course, in
  such a case, the paramagnet is too weak to do the
  actual levitating it just provides a small
  window of stability for an object that is
  actually being lifted by ferromagnetic effects.
  But if we set aside the phenomenon of
  paramagnetism, which is a constantly
  self-adjusting field, and focus strictly on fixed
  fields as are produced by ferromagnets, can we
  achieve stable static levitation? In 1842, Samuel
  Earnshaw proved what is now called Earnshaw's
  Theorem, which states that there is no stable and
  static configuration of levitating permanent
  magnets. (See Earnshaw, S., On the nature of the
  molecular forces which regulate the constitution
  of the luminiferous ether., 1842, Trans. Camb.
  Phil. Soc., 7, pp 97-112.)

71
THE PHISICS AROUND

• The term "permanent magnet" is meant to specify
  ferromagnetism, which is truly a fixed magnetic
  field relative to the magnet. In contrast, the
  phenomena of diamagnetism is not really
  "permanent", both because it requires the
  presence of an externally applied field, and more
  importantly (from the standpoint of Earnshaw's
  theorem) because the diamagnetic field constantly
  adapts to changes in the applied external field.
  This is why stable diamagnet levitation (of which
  superconductors provide the extreme example) is
  possible, in spite of Earnshaw's theorem. It's
  worth noting that Earnshaw's theorem - ruling out
  the possibility of static stable levitation -
  presented scientists at the time with something
  of a puzzle, if not an outright paradox, because
  we observe stable configurations of levitating
  objects every day.

72
THE PHISICS AROUND

• For example, the book sitting on my desk is being
  levitated, and some force is responsible for this
  levitation. Admittedly it may not have been clear
  in Earnshaw's day that the book's interaction
  with the desk was via electromagnetic forces, but
  Earnshaw's theorem actually applies to any
  classical particle-based inverse-square force or
  combination of such forces. Since we observe
  stable levitation (not to mention stable atoms
  and stable electrons), it follows from Earnshaw's
  theorem that there must be something else going
  on, viz., we cannot account for the stable
  structures we observe in nature purely in terms
  of classical inverse-square forces, or even in
  terms of any kind of classical conservative
  forces. In order to explain why stable atoms are
  possible (i.e., why the electrons don't simply
  spiral in and collide with the protons) and why
  other stable structures are possible, it's
  necessary to invoke some other principle(s).
  Something like quantum mechanics and the
  exclusion principle is required.

73
THE PHISICS AROUND

• The proof of Earnshaw's theorem follows closely
  from Gauss's law. Indeed this accounts for the
  generality of its applicability. To consider the
  simplest case, suppose we wish to arrange a set
  of charged particles in such a way that a region
  of stable containment for an electron is
  established. This requires the existence of a
  point in empty space such that the force vector
  everywhere on the surface of an incremental
  region surrounding that point is directed inward.
  But according to Gauss's law, the integral of the
  force vector over any closed surface equals the
  charge contained within the surface. Thus the
  integral of the force over any closed surface in
  empty space is zero, which implies that if it
  points inward on some parts of the surface, it
  must point outward on other parts, so it is
  clearly not a stable equilibrium point. The best
  we could do is have a force of zero over the
  entire surface, but this too is not stable,
  because there is no restorative force to oppose
  any perturbations.

74
THE PHISICS AROUND

• According to Gauss' law, the only point that
  could possibly be a stable equilibrium point for
  an electron is a point where a positive charge
  resides, e.g., a proton. Classically an electron
  would be expected to collapse onto a proton,
  assuming it had no angular momentum. In the
  presence of angular momentum, it's possible to
  have (idealized) stable orbits in the context of
  Newtonian gravitation, because Newton's gravity
  did not radiate energy when charges (i.e.,
  masses) are accelerated. However, electric
  charges were known classically to radiate energy,
  so even naive orbital models were ruled out. This
  made it clear that some other principles must be
  invoked to account for stable configurations of
  electrically charged matter. (In general
  relativity, simple two-body orbital systems also
  radiate energy, in the form of gravitational
  waves, so the same argument can ultimately be
  against the possibility of stable configurations
  for inertially charged matter as well, although
  in this case the rate of energy radiation is so
  low that the configurations are essentially
  stable for practical purposes.)

75
THE PHISICS AROUND

• Incidentally, if we don't require a static
  configuration, then it is possible to achieve
  quasi-stable levitation with permanent magnets by
  spinning the levitated object and using the
  gyroscopic moments to offset the instability. A
  number of interesting devices of this type have
  been constructed. This form of levitation is
  called quasi-stable (rather than stable) because
  the rotation of the levitating object results in
  the emission of energy in the form of
  electromagnetic waves, so eventually the rotation
  will be brought to a stop, and then the system
  will go unstable.

76
THE PHISICS AROUND

• Maglev train
• Magnetic levitation transport, or maglev, is a
  form of transportation that suspends, guides and
  propels vehicles via electromagnetic force. This
  method can be faster than wheeled mass transit
  systems, potentially reaching velocities
  comparable to turboprop and jet aircraft (500 to
  580 km/h). The world's first commercial
  application of a high-speed maglev line is the
  IOS (initial operating segment) demonstration
  line in Shanghai, China that transports people 30
  km (18.6 miles) to the airport in just 7 minutes
  20 seconds (top speed of 431 km/h or 268 mph,
  average speed 250 km/h or 150 mph). Other maglev
  projects worldwide are being studied for
  feasibility. However, scientific, economic and
  political barriers and limitations have hindered
  the widespread adoption of the technology.

77
THE PHISICS AROUND

• All operational implementations of maglev
  technology have had minimal overlap with wheeled
  train technology and have not been compatible
  with conventional railroad tracks. Because they
  cannot share existing infrastructure, maglevs
  must be designed as complete transportation
  systems. The term "maglev" refers not only to the
  vehicles, but to the railway system as well,
  specifically designed for magnetic levitation and
  propulsion.

Technology See also fundamental technology
elements in the JR-Maglev article, Technology in
the Transrapid article, Magnetic levitation
78
THE PHISICS AROUND

• There are two primary types of maglev technology
• electromagnetic suspension (EMS) uses the
  attractive magnetic force of a magnet beneath a
  rail to lift the train up.
• electrodynamic suspension (EDS) uses a repulsive
  force between two magnetic fields to push the
  train away from the rail.

79
THE PHISICS AROUND

• Electromagnetic suspension
• In current EMS systems, the train levitates above
  a steel rail while electromagnets, attached to
  the train, are oriented toward the rail from
  below. The electromagnets use feedback control to
  maintain a train at a constant distance from the
  track.
• Electrodynamic suspension

80
THE PHISICS AROUND

• EDS Maglev Propulsion via propulsion coils
• In Electrodynamic suspension (EDS), both the rail
  and the train exert a magnetic field, and the
  train is levitated by the repulsive force between
  these magnetic fields. The magnetic field in the
  train is produced by either electromagnets (as in
  JR-Maglev) or by an array of permanent magnets
  (as in Inductrack). The repulsive force in the
  track is created by an induced magnetic field in
  wires or other conducting strips in the track.
• At slow speeds, the current induced in these
  coils and the resultant magnetic flux is not
  large enough to support the weight of the train.
  For this reason the train must have wheels or
  some other form of landing gear to support the
  train until it reaches a speed that can sustain
  levitation.

81
THE PHISICS AROUND

• Propulsion coils on the guideway are used to
  exert a force on the magnets in the train and
  make the train move forwards. The propulsion
  coils that exert a force on the train are
  effectively a linear motor An alternating
  current flowing through the coils generates a
  continuously varying magnetic field that moves
  forward along the track. The frequency of the
  alternating current is synchronized to match the
  speed of the train. The offset between the field
  exerted by magnets on the train and the applied
  field create a force moving the train forward.
• Pros and cons of different technologies
• Each implementation of the magnetic levitation
  principle for train-type travel involves
  advantages and disadvantages. Time will tell as
  to which principle, and whose implementation,
  wins out commercially.

82
THE PHISICS AROUND

• Technology   Pros  
  Cons
• EMS Electromagnetic

Magnetic fields inside and outside the vehicle
are insignificant proven, commercially available
technology that can attain very high speeds (500
km/h) no wheels or secondary propulsion system
needed
The separation between the vehicle and the
guideway must be constantly monitored and
corrected by computer systems to avoid collision
due to the unstable nature of electromagnetic
attraction.
Onboard magnets and large margin between rail and
train enable highest recorded train speeds (581
km/h) and heavy load capacity has recently
demonstrated (Dec 2005) successful operations
using high temperature superconductors in its
onboard magnets, cooled with inexpensive liquid
nitrogen
Electromagnetic EDS Electrodynamic
Inductrack System (Permanent Magnet EDS)
Failsafe Suspension