1) Certain metals exhibit zero electrical resistance below a critical temperature known as the superconducting transition temperature. This phenomenon is called superconductivity.
2) Superconductors can be classified as either Type I or Type II, depending on their behavior in magnetic fields. Type I superconductors exhibit the Meissner effect and have a sharp transition to the normal state, while Type II superconductors allow some magnetic field penetration.
3) The BCS theory explains superconductivity as arising from electrons forming Cooper pairs via an attractive interaction mediated by phonons in the crystal lattice. The Cooper pairs behave as a superfluid with zero resistance.
Basically i have tried giving every details about the phenomenon Superconductivity in the simplest way. This is my first upload.I'll be very glad if u all give your valuable feedback. Thank u.
Properties of superconductors, Effects of the magnetic field, variation of resistance with temperature, Meissner Effect, isotope effect, Energy Gap, Coherence Length, BCS Theory, Types of superconductors ,
Basically i have tried giving every details about the phenomenon Superconductivity in the simplest way. This is my first upload.I'll be very glad if u all give your valuable feedback. Thank u.
Properties of superconductors, Effects of the magnetic field, variation of resistance with temperature, Meissner Effect, isotope effect, Energy Gap, Coherence Length, BCS Theory, Types of superconductors ,
Superconducting material and Meissner effectMradul Saxena
The project report gives brief explanation of the phenomenon of superconductivity and also give introduction to superconducting materials and their types, properties and their applications.
This presentation covered most of topics related to the superconductor like properties of superconductors, the meissner effect, type 1 and type 2 superconductors their properties and diagram difference between type 1 and type 2 superconductors, Penetration depth,Josephson effect and it's applications, BCS theory, cooper pairs, flux quantization, Effect of current etc...
Superconductivity is the ability of certain materials to conduct electric current with practically zero resistance. This capacity produces interesting and potentially useful effects. For a material to behave as a superconductor, low temperatures are required.
Superconducting material and Meissner effectMradul Saxena
The project report gives brief explanation of the phenomenon of superconductivity and also give introduction to superconducting materials and their types, properties and their applications.
This presentation covered most of topics related to the superconductor like properties of superconductors, the meissner effect, type 1 and type 2 superconductors their properties and diagram difference between type 1 and type 2 superconductors, Penetration depth,Josephson effect and it's applications, BCS theory, cooper pairs, flux quantization, Effect of current etc...
Superconductivity is the ability of certain materials to conduct electric current with practically zero resistance. This capacity produces interesting and potentially useful effects. For a material to behave as a superconductor, low temperatures are required.
Fundamentals of Superconductivity and its applicationsPraveen Vaidya
"Superconductivity" is a topic related to Physics, Chemistry and Engineering and Technology, anybody who would like to know about superconductor can read this article. This article explains about the fundamental's of superconductors, its various effects like Meissner effect, its theory and applications in MRI, Magneto encephalography, flying vehicle or levitating vehicles etc.
Superconducting materials have greater significance in present era. This phenomena must be studied completely logical and if knowledge about SC is fetched a little its very interesting to go ahead. In recent years this property of materials are developed and obtained clearly, they are completely implemented in transportation, switching etc., This slides can give you basics in superconducting behavior and materials. Trends have been made to use them in everyday and it gives user friendly behavior.
The fascinating phenomenon of superconductivity and its potential applications have attracted the attention of scientists, engineers and businessmen.
Superconductivity was discovered in 1911 by Heike Kamerlingh Onnes, as he studied the properties of metals at low temperatures.
Basic Information regarding superconductors.
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature.
This power-point presentation include
1. Introduction to Superconductors
2. Discovery
3. Properties
4. Important factors
5. Types
6. High Tc Superconductors
7. Magnetic Levitation and its application
8. Josephson effect
9. Application of superconductors
#Tip- You can further add videos which are available in vast amount on YouTube regarding superconductivity(specially magnetic levitation)
P.S.Does not contain information about Cooper pairs and BCS theory
An Overview of Superconductivity with Special Attention on Thermodynamic Aspe...Thomas Templin
Superconductors are special types of conductors that exhibit a variety of physical phenomena such as zero resistivity, the absence of thermoelectric effects, ideal diamagnetism, the existence of a Meissner effect, and flux quantization. The observed phenomena mean that superconductivity is a well-defined thermodynamic equilibrium state/phase that does not depend on a sample’s history. Changes of phase are entirely reversible, and once a substance has come to equilibrium with its surroundings, there is no memory of its past history.
A variety of theoretical approaches have been developed to explain superconductivity. These include the two-fluid model of superconductivity, the Ginzburg-Landau theory, and the BCS model. These models are most suitable to explain the phenomena associated with type-I superconductors, i.e., the types of superconductors that only exist when the external magnetic field is below a relatively low threshold value of Bc as well as below a transition temperature Tc close to 0 K. In the 1980s a new type of superconductors was discovered, called type-II superconductors. Type-II materials are characterized by the coexistence of normally conducting and superconducting states as well as relatively high values of the critical field and transition temperature. Type-II superconductors have been used in a variety of technological applications, such as superconducting electromagnets, MRI, particle accelerators, levitating trains, and superconducting quantum-interference devices (SQUIDs).
The superconducting state has a lower free energy than the normal state. The exclusion of the magnetic field from a superconductor leads to an increase in the free energy. The Meissner effect thus implies the existence of a thermodynamical critical field for which these two effects balance out. Knowing only the experimental temperature dependence of the critical field, the Gibbs free energy, the entropy, and the specific heat that characterize the superconducting phase can be determined.
SUPERCONDUCTIVITY BY SATYAAPTRAKASH.pptxPokeDSatya
Superconductivity presentation ppt on the presentation of HIL ok sir thank you so much sir thank thank God for friendly and Goddess are you still have a great you more than one of the mountain of the mountain you .
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
1. LECTURE NOTES ON SUPERCONDUCTIVITY
T
ρ
TC
Superconductivity
Certain metals and alloys exhibit almost zero resistivity when they are cooled to
sufficiently low temperature. This phenomenon is called super conductivity. The
temperature at which the resistivity drops to zero is known as critical temperature.
The materials which exhibit the phenomena are known as superconductors.
The super conductivity was first observed in Hg at 4 K.
Properties:
Transition temperature is different for different substances.
Pure substances the transition temperature is very sharp.
Substances which are having the valence electron 2 to 8 exhibit
superconductivity.
Superconducting elements lie in the inner columns of the periodic table.
Materials having odd no.of electrons are favourable and even no of valence
electrons are unfavorable.
Materials having high normal resistivities exhibit superconductivity.
Z ρ > 106
. Z : No.of valence electrons show superconductivity.
Ferromagnetic and anti ferromagnetic materials are not superconductors.
The resistivity approaches to zero as the temperature is reduced to 0K.
Magnetic flux lines are expelled out by the superconducting material.
There is a discontinuous change in the specific heat.
There is a small change in thermal conductivity and volume of the materials.
Current persist in the superconducting ring for a long time.
1
2. LECTURE NOTES ON SUPERCONDUCTIVITY
HC
SC
Normal state
TC
Effect of magnetic field
Superconducting state of a metal mainly depends on temperature and strength of the
magnetic field. Superconductivity disappears if the temperature of the specimen is
raised above TC or strong magnetic field is applied.
When the temperature of the specimen is below TC, in the absence of the magnetic
field the substance is in the superconducting state. When the strength of the field
reaches the critical value HC, the superconductivity disappears.
The dependence of the critical field upon the temperature is given by
HC(T) = HC(0) [1−[T /TC ]
2
]
At T = TC, HC = 0.
HC(0) is the critical field at 0 K.
2
3. LECTURE NOTES ON SUPERCONDUCTIVITY
Meissner effect
When a weak magnetic field is applied to a superconducting specimen at a
temperature below transition temperature TC, the magnetic flux lines are expelled as
shown in fig. The specimen acts as an ideal diamagnet. This effect is called Meissner
effect.
B = )M(Hμo
When the specimen is in superconducting state,
B = 0
MH
M
M
H
M
1-χ
This is diamagnetic behavior.
Effect of current:
An electric current flowing through the superconducting material, produce the
magnetic field. As the current is increased, the magnetic field is also increases and at
a particular value of the current IC, the magnetic field reaches the critical value and the
superconductivity disappears. The current at this position is called critical current.
Critical current is given by
CC rHI 2
3
4. LECTURE NOTES ON SUPERCONDUCTIVITY
SC
Normal
HC
H
M
Type I and Type II superconductors.
Based on diamagnetic response ( Meissner effect ) superconductors can be classified
as Type I and Type II superconductors.
Superconductors exhibiting a complete Meissner effect (Perfect diamagnetism) are
called Type I superconductors. When the magnetic field is increased from zero, at HC,
the superconductivity disappears. The transition from superconducting state to
normal state is sharp.
Examples: Al, Zn, Hg, Sn
Hc2
Hc1
Normal
vortex
M
H
4
5. LECTURE NOTES ON SUPERCONDUCTIVITY
TC
T
S
SC
Normal
SC
Normal
TC
T
CV
In Type II superconductors, upto the field 1CH the specimen is in a pure
superconducting state. The substance exhibits perfect Meissner effect upto the field
1CH . When the field is increased beyond 1CH ( lower critical field ), the magnetic
flux lines start penetrating. When the field is increased further, at 2CH , the
superconductivity disappears. The field 2CH is known as upper critical field. After
2CH , the substance is in the normal state. Between 1CH and 2CH , the substance
is in the mixed state. This region is known as Vortex-region. In this region the
substance exhibits incomplete Meissner effect. These substances can carry high
current densities.
Example: Zr, Nb
Entropy
Entropy is a measure of the disorder of a system. In normal metals with decrease of
temperature, entropy decreases linearly. Below the critical temperature the entropy
decreases rapidly with temperature. This means that the superconducting state is
more ordered state.
Specific heat
In the case of normal metals the specific heat decreases linearly with the temperature.
But in the superconducting materials, at the transition temperature, there is the
discontinuity in the specific hear curve.
5
6. LECTURE NOTES ON SUPERCONDUCTIVITY
Energy gap
In the case of normal metals at T=0 K, all the energy states are completely filled
below EF, and the states above are completely empty. But in the case of super
conductors, below TC, there exists an energy gap. This is due to the pairing of
electrons which are known as super electrons. This energy gap disappears if the
temperature is above TC. Moreover this energy gap is very small as compared to the
gaps in semiconductors and insulators.
Isotope effect
For superconducting materials the transition temperature varies with the average
isotopic mass, M, which is given by
MTC
Or
constantCTM
α is isotopic effect coefficient which is approximately equal to 0.5.
Josephson effect:
Let us consider a thin insulating layer sandwiched between two superconductors as
shown in fig. Since the barrier is so thin quantum mechanically electrons can tunnel
from superconductor 1 to 2. In addition to normal tunneling of single electrons, the
super electrons ( Cooper pairs ) also tunnel through the insulating layer even at zero
potential difference across the junction. This is known as Josephson effect.
6
7. LECTURE NOTES ON SUPERCONDUCTIVITY
D.C. Josephson effect:
According to Josephson, when tunneling occurs through the insulator it introduces a
phase difference o .
The tunneling current is given by
)sin( ooII
oI is the maximum current that flows through the junction without any potential
difference. With no applied voltage a d.c current flows across the junction. This is
called D.C. Josephson effect.
A.C. Josephson effect
Let us assume that a static potential is applied across the junction. This introduces an
additional phase during the tunneling. According to quantum mechanics, the
additional phase difference is given by
Et
Energy E = 2 e Vo Vo : applied potential
=
teV2 o
I = Io Sin
teV2 o
o
This is of the form
I = Io Sin ωto
Therefore,
o2eV
ω . This represents an alternating current with angular frequency
. This is the A.C. Josephson effect. When an electron pair crosses the junction a
photon of energy o2eVω is emitted or absorbed.
7
8. LECTURE NOTES ON SUPERCONDUCTIVITY
Fig. V-I Characteristic of Josephson effect Fig. A.C. Josephson effect
1. When 0oV , there is a constant flow of d.c. current IC through the junction.
2. When
co VV , a constant current IC flows.
3. When
co VV , the current oscillating with a frequency .
Application of Josephson effect.
1. To generate microwaves.
2. To define standard volt.
3. To measure very low temperatures.
4. Used for switching of signals.
Flux quantization:
The magnetic flux enclosed by the superconducting ring is quantized. It is an integral
multiples of fundamental quantum of flux. The magnetic flux enclosed by a
superconducting ring is given by
e
h
n
2
Or
on
Where
8
9. LECTURE NOTES ON SUPERCONDUCTIVITY
H
x
0H
e
H o
e
h
o
2
and n = 1, 2, 3, …..
o is the flux quantum and is called Fluxon. Its value is 2.07 X 10-15
Weber.
Superconducting Ring
London penetration depth:
When a superconducting material is placed in a external magnetic field, a current is
set up on the surface of the material. The existence of the surface current implies that
the applied magnetic field penetrates some distance into the superconductor, decaying
exponentially to zero over a length , as shown in fig. The length is called the
London penetration depth.
According to London the decrease of magnetic field penetration is given by
9
10. LECTURE NOTES ON SUPERCONDUCTIVITY
x
HH exp)0(
Where is given by
2
1
2
en
m
so
At
e
H
Hx
)0(
,
2
1
4
4
1)0()(
CT
T
T
The penetration depth can be defined as the depth from the surface at which the
magnetic flux density decreases to 1/e of its initial value at the surface.
BCS theory
This theory was proposed by Bardeen, Cooper and Schrieffer.
1. According to this theory, in the superconductors the electrons are paired
together via electron-lattice-electron interaction.
2. Consider an electron passing through the lattice of positive ions. The electron
is attracted by the positive ion and the lattice gets deformations. This ion
attracts another electron. Thus two electrons attract each other via the lattice
interaction which is said to be due to exchange of virtual phonons.
3. The interaction process in terms of the wave vectors can be written as
'
11 kqk and '
22 kqk
4. Therefore '
2
'
121 kkkk . That is net wave vector of the pair is conserved.
The momentum is transferred between the electrons. The electron pair is
called Copper pair or Cooper electron.
10
11. LECTURE NOTES ON SUPERCONDUCTIVITY
Fig. The exchange of virtual phonons between the two electrons (Cooper Pair)
5. The spins of Cooper electrons are always opposite in direction.
6. In a typical superconductor, there will be as many as 106 pairs.
7. The Cooper pairs form a collective state and they drift cooperatively through
the material. Therefore the superconducting state is a highly ordered state.
8. The collision of Cooper pairs with the lattice is vary rare therefore the
resistivity is zero.
9. This Cooper pairs are responsible for the super conductivity.
Application of Superconductors:
1. Electric generators
The low loss superconducting coil when rotated in an external magnetic field
power is generated. This principle can be used to generate high power to low
power. Another advantage is the small size and weight of the materials.
30 kVA Superconducting Generator
2. Low loss transmission lines and transformers
Since the resistance is almost zero in the superconducting state, the power loss
( Joule’s loss) during transmission is very low. Hence they can be used as
electric cables. Superconductors can be used for winding of a transformer.
Superconducting Transformer
11
12. LECTURE NOTES ON SUPERCONDUCTIVITY
3. Magnetic levitation
Meissner effect is the basis of magnetic levitation. The floating of the
superconducting material in the magnetic filed is known as magnetic
levitation. This can be used for high speed transportation.
Magnetic levitation train
4. Generation of high magnetic fields
Current carrying superconducting ring can produce a magnetic field of the
order of 50 T with low power.
5. Fast electrical switching.
A superconductor posses two states, the superconducting state and normal
state. The transition from these two states depending upon the current density.
This can be used as a switch known as cryotron. This can be used in the
development of super fast computers.
6. Logic and storage functions in computers.
Josephson effect is used in constructing the memory elements of super
computers.
7. SQUIDS
Super conducting quantum interference devices are known as SQUIDS. Two
Josephson junctions mounted on a superconducting ring forms this SQUIDS.
They are based on the flux quantization that is the flux passing through the
ring is quantized. Very minute change in the flux can be detected by this
SQUIDS sensors. These are used to study the signals from the brain and heart.
12