SIMPLE AND ACCESSIBLE SLIDES ON POLARIZATION. IT INCLUDES SLIDES ON DOUBLE REFRACTION , CALCITE CRYSTALS, HUYGEN'S THEORY , NEGATIVE AND POSITIVE CRYSTALS,...
Polarization of light, Types of Polarization, Plane polarized light and its production, Circular Polarization, Elliptical Polarization, E -ray , O-ray, Positive and negative crystals, Quarter wave plate and half wave plate.
NANO106 is UCSD Department of NanoEngineering's core course on crystallography of materials taught by Prof Shyue Ping Ong. For more information, visit the course wiki at http://nano106.wikispaces.com.
POLARIZATION
Polarization is a property of waves that can oscillate with more than one orientation.
Electromagnetic waves such as light exhibit polarization, as do some other types of wave, such as gravitational waves.
Sound waves in a gas or liquid do not exhibit polarization, since the oscillation is always in the direction the wave travels.
Polarization of light, Types of Polarization, Plane polarized light and its production, Circular Polarization, Elliptical Polarization, E -ray , O-ray, Positive and negative crystals, Quarter wave plate and half wave plate.
NANO106 is UCSD Department of NanoEngineering's core course on crystallography of materials taught by Prof Shyue Ping Ong. For more information, visit the course wiki at http://nano106.wikispaces.com.
POLARIZATION
Polarization is a property of waves that can oscillate with more than one orientation.
Electromagnetic waves such as light exhibit polarization, as do some other types of wave, such as gravitational waves.
Sound waves in a gas or liquid do not exhibit polarization, since the oscillation is always in the direction the wave travels.
Polarization of Light and its Application (healthkura.com)Bikash Sapkota
Download link ❤❤https://healthkura.com/eye-ppt/29/❤❤
Dear viewers Check Out my other piece of works at ❤❤❤ https://healthkura.com/eye-ppt/ ❤❤❤
polarization of light & its application.
PRESENTATION LAYOUT
Concept of Polarization
Types of Polarization
Methods of achieving Polarization
Applications of Polarization
POLARIZATION
Transforming unpolarized light into polarized light
Restriction of electric field vector E in a particular plane so that vibration occurs in a single plane
Characteristic of transverse wave
Longitudinal waves can’t be polarized; direction of their oscillation is along the direction of propagation.............
For Further Reading
•Optics by Tunnacliffe
•Optics and Refraction by A.K. Khurana
•Principle of Physics, Ayam Publication
•Internet
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation
The crystal structure notes gives the basic understanding about the different structures crystalline materials and their properties and physics of crystals. It also throw light on the basics of crystal diffraction
Polarization of Light and its Application (healthkura.com)Bikash Sapkota
Download link ❤❤https://healthkura.com/eye-ppt/29/❤❤
Dear viewers Check Out my other piece of works at ❤❤❤ https://healthkura.com/eye-ppt/ ❤❤❤
polarization of light & its application.
PRESENTATION LAYOUT
Concept of Polarization
Types of Polarization
Methods of achieving Polarization
Applications of Polarization
POLARIZATION
Transforming unpolarized light into polarized light
Restriction of electric field vector E in a particular plane so that vibration occurs in a single plane
Characteristic of transverse wave
Longitudinal waves can’t be polarized; direction of their oscillation is along the direction of propagation.............
For Further Reading
•Optics by Tunnacliffe
•Optics and Refraction by A.K. Khurana
•Principle of Physics, Ayam Publication
•Internet
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation
The crystal structure notes gives the basic understanding about the different structures crystalline materials and their properties and physics of crystals. It also throw light on the basics of crystal diffraction
Polarization and it's application in OphthalmologyRaju Kaiti
Polarization, types of polarization, mechanisms to produce polarization, Applications of polarization, precautions with polarizing sunglasses, ophthalmic uses of polarization
This presentation covers topics related to polarization of light, methods of producing polarised light, optical activity, birefringence etc.
This would help for quick revision of the topics.
DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
Toxic effects of heavy metals : Lead and Arsenicsanjana502982
Heavy metals are naturally occuring metallic chemical elements that have relatively high density, and are toxic at even low concentrations. All toxic metals are termed as heavy metals irrespective of their atomic mass and density, eg. arsenic, lead, mercury, cadmium, thallium, chromium, etc.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Salas, V. (2024) "John of St. Thomas (Poinsot) on the Science of Sacred Theol...Studia Poinsotiana
I Introduction
II Subalternation and Theology
III Theology and Dogmatic Declarations
IV The Mixed Principles of Theology
V Virtual Revelation: The Unity of Theology
VI Theology as a Natural Science
VII Theology’s Certitude
VIII Conclusion
Notes
Bibliography
All the contents are fully attributable to the author, Doctor Victor Salas. Should you wish to get this text republished, get in touch with the author or the editorial committee of the Studia Poinsotiana. Insofar as possible, we will be happy to broker your contact.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
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.
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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
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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.
2. HISTORICAL CONTEXT
•Before the beginning of the nineteenth century, light was considered to
be a stream of particles.
• The particles were either emitted by the object being viewed or
emanated from the eyes of the viewer.
•Newton was the chief architect of the particle theory of light.
• He believed the particles left the object and stimulated the sense of sight upon
entering the eyes
3.
4. NATURE OF LIGHT
• The optical phenomena like interference and diffraction exhibited
by the light establishes its wave nature.
• The nature of this wave is given by the phenomena of Polarization.
• Light is an ElectroMagnetic Wave and Polarization proves Light to be
a transverse Wave.
• Thus Light has an Electric vector (E) and a Magnetic vector(M)
vibrating in perpendicular directions.
• Electric field vector is of primary imporatance.
6. POLARIZATION
• Polarization of light waves is the phenomenon of restricting the plane
of vibration of Electric field vector of light in a definite plane.
7. There are three type of polarized light
1) Plane Polarized Light (ppl or lpl)
2) Circularly Polarized Light (cpl)
3) Elliptically Polarized Light (epl)
10. PRODUCTION OF PLANE POLARIZED
LIGHT
• 1) By Reflection
• 2) By Refraction
• 3) By Selective Absorption( Dichroizm )
• 4) By Scattering
• 5) By Double Reflection
11. DOUBLE REFRACTION OR BIREFRINGENCE
• When ordinary light is allowed to pass through a calcite or quartz , it
splits into two refracted beams(O-ray &E –ray )and both are plane
polarized lights.
13. . HUYGEN’S PRINCIPLE
• Huygens’ principle, in optics, a statement that all points of a wave front of light in a vacuum or
transparent medium may be regarded as new sources of wavelets that expand in every direction
at a rate depending on their velocities.
• “ Every point on a wave-front may be considered a source of secondary spherical wavelets which
spread out in the forward direction at the speed of light. The new wave-front is the tangential
surface to all of these secondary wavelets.”
• Proposed by the Dutch mathematician, physicist, and astronomer ,Christiaan Huygens, in 1690, it
is a powerful method for studying various optical phenomena.
A surface tangent to the wavelets constitutes the new wave front and
is called the envelope of the wavelets. If a medium is homogeneous and has the same properties
throughout (i.e., is isotropic), permitting light to travel with the same speed regardless of its
direction of propagation, the three-dimensional envelope of a point source will be spherical;
otherwise, as is the case with many crystals, the envelope will be ellipsoidal in shape (see double
refraction). An extended light source will consist of an infinite number of point sources and may
be thought of as generating a plane wave front.
14. A wavefront is a surface over which an optical wave has a constant
phase. For example, a wavefront could be the surface over which the
wave has a maximum (the crest of a water wave, for example) or a
minimum (the trough of the same wave) value. The shape of a
wavefront is usually determined by the geometry of the source. A
point source has wavefronts that are spheres whose centers are at
the point source.
15. HUYGEN’S THEORY OF DOUBLE
REFRACTION
• According to Huygen’s theory , a point in a doubly
refracting or birefringent crystal produces 2 types
of wavefronts:
The wavefront corresponding to the O-ray Spherical wavefront
oThe ordinary wave travels with same velocity in all directions and so the
corresponding wavefront is spherical.
The wavefront corresponding to the E-ray Ellipsoidal wavefront
oExtraordinary waves have different velocities in different directions, so the
corresponding wavefront is elliptical.
19. NEGATIVE CRYSTALS
• Negative crystals are crystals in which refractive index corresponding to E-Ray (nE
) is less than the refractive index corresponding to O-Ray ( nO ) in all directions
except for Optic axis.
• The E-Ray travels faster than O-Ray except along the Optic axis.
• The spherical O-Wavefront is entirely within the ellipsoidal E -Wavefront.
• Ex: Calcite , Tourmaline ,Ruby ...
20. POSITIVE CRYSTALS
• Positive crystals are crystals in which refractive for O-Ray is less than that for E-
Ray(nO<nE).
• The velocity of O-Ray is greater than or equal to the velocity of E-Ray.
• The ellipsoidal E-wavefront is entirely within the spherical O-wavefront.
• Example : Quartz (SiO2), Sellaite (MgF2),Rutile (TiO2),…
21. OPTIC AXIS
• Optic axis of a crystal is the direction in which a ray of transmitted light suffers no
birefringence (double refraction). Light propagates along that axis with a speed
independent of its polarization.
• For all rays not traveling along the optic axis, the velocity is determined by a pair
of refractive indices called the ordinary refractive index no and the extraordinary
refractive index ne, and the path of an incident ray is split into two rays, the so-
called o-rays and e-rays.
• According to number of optic axes crystals are divided as : Uniaxial and Biaxial
crystals.
22. UNIAXIAL MINERALS
• Uniaxial minerals are defined as minerals that have one and only one direction along which light
passes with the vibrations (remember, vibrations are always perpendicular to the direction of
propagation) moving at equal speed (and hence with a unique resistance or refractive index).
• Uniaxial minerals are ones that crystallize in the tetragonal, hexagonal and trigonal systems.
• Light passing through a uniaxial crystal at an orientation other than the optic axis will therefore
break into 2 rays: an ordinary ray “o”, and an extraordinary ray “e”.
• A mineral in which the extraordinary ray is slower than that of the ordinary one (i.e. > ) is
considered to be optically positive, and vice versa.
• Examples: Calcite , Quartz
23. BIAXIAL MINERALS
• Are minerals with 2 optic axes; i.e. 2 directions along which the light shows no birefringence and
vibrates in a circular section with a unique constant refractive index. (known as ).
• Biaxial minerals are ones that crystallize in the orthorhombic, monoclinic and triclinic systems.
• Biaxial minerals have 3 indices of refraction: , , and , listed in order of increasing values (i.e.
is always > > ).The maximum birefringence of a biaxial mineral will be: - .
• Light incident along one of the two optic axes will vibrate in one direction only with a refractive
index value given by the radius of the circular section to which it is perpendicular. If has a
value closer to than to , the mineral is biaxial positive, and vice versa.
• A light ray incident at any angle to the optic axes will still split into 2 rays. However, unlike in the
case of uniaxial minerals, both rays are extraordinary. One of these extraordinary rays will vibrate
with a refractive index of a value between and (called ’), the other between and (called
’).
• Examples : borax, sugar, feldspar, and niter.
25. CALCITE CRYSTALS
• Calcite is the crystallized form of Calcium Carbonate(CaCO3).
• It is the most stable polymorph of Calcium Carbonate( CaCO3).
• It is called Iceland Spar due to its large availabilities in Iceland.
• Color is white or none, though shades of gray, red, orange, yellow, green,
blue, violet, brown, or even black can occur when the mineral is charged
with impurities.
• Calcite is transparent to opaque and may occasionally
show phosphorescence or fluorescence.
• It exists in nature in several forms but cleaves very perfectly along 3
directions forming a Rhombohedron.
26.
27. Calcite or Calcium
carbonate (CaCO3)
3-fold symmetry
CO3 carbonate
groups are all in
planes normal to
the Optic axis.
Large
Birefringence
28. It is possible to cleave calcite and form sharp faces that create a cleavage form (rhombohedron) as
shown below possessing faces of a parallelogram with angles of 78.08 and 101.92. There are only two
blunt (not sharp) corners (labeled A and B) where the surface planes meet. A line passing
through the vertex of each of these blunt corners and oriented so that it makes equal angles with
each face (45.5) and each edge (63.8) is clearly an axis of 3-fold symmetry and called the Optical
Axis.
A
B
The 3-fold axis is related to the 3-fold
symmetry of the CO3 carbonate groups
shown previously and the line
representing this axis must be then
parallel to the optic axis of the crystal, as
shown.
The direction in which the ray suffer no
Double refraction in the crystal is the
Optical Axis.
Any line in the crystal parallel to this
direction is also an Optical Axis.
29.
30. The birefringent property of calcite
leads to the formation of two images
as shown in examples.
The images are related to the
existence of ordinary rays (o-rays)
and extraordinary rays (e-rays). An
analysis of these rays shows that both
these rays are linearly polarized.
Colorless Calcite Rhombohedron with a
long edge of ~12 cm.
31. PRINCIPLE SECTION
• For the class of crystals called uniaxial, there is only one direction where all light
rays travel along the same path at a constant velocity.
• This direction defines the optic axis or principal axis, and any plane that contains
the optic axis is called a principal plane (sometimes called a principal
section) - the plane contain optic axis and normal to any cleavage face.
The optic axis is not a specific line, but indicates a direction in the crystal where
there is no double refraction.
• 3 principle sections through a point are observed- one for each pair of opposite
faces.
32. The o-wave, with its perpendicular
polarization, exhibits a single propagation
velocity, v. The wave stimulates
numerable atoms at the surface
producing a source of radiating spherical
wavelets, the summation of which leads
to a plane wave propagation as in the
case of an isotropic medium like glass.
33. In the above figure, E lies in the principal section, defining the
e-wave, and E = E|| + E, where E|| || Optic-axis. Each
component will propagate with velocities, v|| and v,
respectively. The result is that a point at the interface emits
waves that are elongated into an ellipsoid of revolution rather
than a spherical shape.
34. • A Principle section always cut the surfaces of a
Calcite crystals in a parallelogram with angles
of 109o and 71o.