A method of obtaining an Infrared spectrum by measuring the interferogram of a sample using an interferometer, then performing a Fourier Transform upon the interferogram to obtain the spectrum.
IR SPECTROSCOPY, INTRODUCTION, PRINCIPLE, THEORY, FATE OF ABSORBED RADIATION, FERMI RESONANCE, FINGERPRINT REGION, VIBRATIONS, FACTORS AFFECTING ABSORPTION OF IR RADIATION, SAMPLING TECHNIQUES, APPLICATIONS OF IR SPECTROSCOPY.
Introduction to Activation analysis using Neutron
Baisc Principle of NAA
Instrumental NAA
Characteristics of INAA
Advantages, Limitation and Applications of INNA
A method of obtaining an Infrared spectrum by measuring the interferogram of a sample using an interferometer, then performing a Fourier Transform upon the interferogram to obtain the spectrum.
IR SPECTROSCOPY, INTRODUCTION, PRINCIPLE, THEORY, FATE OF ABSORBED RADIATION, FERMI RESONANCE, FINGERPRINT REGION, VIBRATIONS, FACTORS AFFECTING ABSORPTION OF IR RADIATION, SAMPLING TECHNIQUES, APPLICATIONS OF IR SPECTROSCOPY.
Introduction to Activation analysis using Neutron
Baisc Principle of NAA
Instrumental NAA
Characteristics of INAA
Advantages, Limitation and Applications of INNA
An Infrared spectrum represents a fingerprint of a sample with absorption peaks which correspond to the frequencies of vibrations between the bonds of the atoms making up the material-Because each different material is a unique combination of atoms, no two compounds produce the exact same spectrum, therefore IR can result in a unique identification of every different kind of material!
An Infrared spectrum represents a fingerprint of a sample with absorption peaks which correspond to the frequencies of vibrations between the bonds of the atoms making up the material-Because each different material is a unique combination of atoms, no two compounds produce the exact same spectrum, therefore IR can result in a unique identification of every different kind of material!
Introduction to Fourier Transfer Infrared SpectroscopyRahulVerma550005
The preferred method of infrared spectroscopy is known as Fourier Transform InfraRed (FT-IR). Infrared spectroscopy involves passing IR photons through a sample. The sample absorbs some of the infrared light and passes some of it through (transmitted). The resulting spectrum depicts the sample's molecule absorption and transmission, resulting in a molecular fingerprint.
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.
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.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
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.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
3. ELECTROMAGNETIC SPECTRUM
UV VIS NIR IR Far IR Microwave
10-5
10-5 10-4 10-3 10-2 10-1
Wavelength (cm)
Energy
0.78 2.5 25 1000Wavelength (mm)
Wavenumber (cm-1) 12,800 4000 400 10
4. Discovery of Infrared Radiation
William Herschel
1738-1822
German Astronomer
The infrared radiation was
discovered in 1800.
Infra = Lower
Infrared = Lower energy
radiation.
He observed an invisible radiation
in solar spectrum having lower
energy than red light, by means
of its effect on a thermometer.
5. Electromagnetic radiation is an oscillating
electric force field transmitted through
space in the form of a transverse wave
Responsible for phenomena such as
transmission, absorption, refraction and
reflection
Wave Properties
6. PROPERTIES OF LIGHT
n = frequency (cycle / second)
0 2 4 6 8 10
-1.0
-0.5
0.0
0.5
1.0
lOne cycle
nl = cA
A = amplitude
c = speed of light (3.0 * 1010 cm / sec)
l = wavelength (nm , μm )
7. E = Energy (ergs)
h = Planck’s Constant (erg sec)
c = Speed of light (μm/sec)
l = Wavelength (μm)
n = Frequency (cycles/sec)
E = hc/l = hn
ENERGY OF LIGHT
9. High energy radiation causes
Electronic transition
Low energy radiation causes
Vibrational transition
Rotational transition
ABSORPTION OF RADIATION
10. ABSORPTION OF RADIATION
Energy
Vibrational transition
Rotational
transition R
v1
v2
v0
5
4
3
2
1
0
Electronic
transition
E1
E0
v0
v1
v2
E = hn in which h is Planck’s constant (6.626 * 10-34 Joules
and n is the frequency of the radiation
11. Vibrational motion
•A polyatomic molecule containing N atoms
will have 3N possibilities for motion
•Of these 3N possibilities or degree of
freedom, 3 must be attributed for the
translation of the entire molecule
•The remain 3N – 3 possibilities are for
rotation and internal vibration in the
molecule
•Therefore
3N – 3-2 is for linear molecules
3N – 3-3 is for non-linear molecules
12. Types of Vibrations
1. Stretching Vibrations
Bond length changes
2. Bending Vibrations
Bond angle changes
14. When the molecule is irradiated with
electromagnetic radiation, the vibrating bond
will absorb energy if the frequencies of the
light and the vibration are identical
Each of the different vibration modes give rise
to different absorption band
Absorption of Infrared Radiation
15. Absorption of Infrared Radiation
A molecule must undergo a net change in
dipole moment as a consequence of
vibrational or rotational motions in order to
absorb infrared radiation
16. Can all vibrations absorb IR?
Frequencies fall outside the normal infrared regions
Vibration does not produce a fluctuating dipole therefore
cannot interact with fluctuating electric fields of the
infrared light
Cl H
N N
Example of Dipole and Dipole movement
• When HCl vibrates, the
dipole (charge separation)
increases
• N2 has no dipole and is
infrared inactive
23
18. GROUP WAVENUMBERS
Associated with the movements of a few atoms
Largely independent of the rest of the
molecule
Examples: C = O, C - Cl, NH, CH and OH
19. Fingerprint Region
• Complex region of the infrared spectrum
below 1500 cm-1.
• Functional group region
• Vibrational modes involve many atoms
• Characteristic of the molecule as a whole
20. Regions of Infrared Spectrum
4000 2500 2000 1500 625
2.5 4 5 7 16
Wavenumber (cm-1)
Wavelength (10-6m)
21. OVERTONE
Relatively weak intensity that may not be observed
Found in high wavenumber regions
Appear at integer multiples of fundamental vibrations
Occur at frequency about 2 or 3 times that of the
fundamental lines
Not very common in mid-infrared spectra of molecules
22. Infrared Window Materials
Used for transmission infrared radiation
Used as a media for powdered samples
Used as a cell for liquid samples
23. Consideration of Window Materials
wavenumber transmission range
chemical properties of sample and crystal
physical properties of materials
cost of materials
25. Sodium Chloride NaCl
Widely used material for infrared cell windows
Relatively the lowest cost
Wide transmission range
Low reflection losses
Soluble in water and glycerine
Slightly soluble in alcohol
Hygroscopic, thus fog easily
26. Potassium Bromide KBr
Most widely used window material
Good resistance to thermal and mechanical shock.
Wider transmission range
Dissolve readily in water, glycerine and
Alcohol
More hygroscopic than sodium chloride
Scratches and deforms much readily than
sodium chloride
27. Calcium Fluoride CaF2
Insoluble in water
Useful for aqueous and deuterium oxide
solutions analysis
Good resistance to most acids and alkalis but is
attacked by ammonium salts
Hard , and hence high mechanical strength
Limited transmission range
28. KRS-5 (Thallium Bromide/ Iodide)
Difficult to dissolve in water
Attacked by aqueous solutions of high pH and
solutions of phosphates
Toxic, usually only harmful if absorbed through a
cut or ingested
Widely used as an internal reflection plate in ATR
Difficult to polish
29. Germanium Ge
Inert to chemicals
Insoluble in water but attacked by hot
Sulfuric acid
Hard and very brittle
Mostly used for ATR prism
High reflection losses which lead to low
transmission levels
30. Quartz/ Silica
Commonly used for near infrared region
Very resistant material
Soluble in hydrofluoric acid and slightly soluble in
alkalis
Three types namely, natural, ultraviolet and
infrared grade
31. Diamond
Hardest window material used in infrared
spectroscopy
Superior physical and chemical properties
Mostly used for ATR reflector plate for
intractable samples
Extremely expensive
Having IR absorption 3000~1500cm-1
32. Thumb rules for IR interpretation
Rule 1:
Bending is easier than stretching-- happens at lower energy (lower wavenumbe
C-H Stretch Alkane 2800-3000 cm-1
C-H Bend Alkane 1300-1400 cm-1
Rule 3:
Heavier atoms move slower than lighter atoms
C-Cl 550-850 O-H more than 3300
C-H more than 2800
Rule 2:
Triple bond ˃ Double bond ˃ Single bond
Alkyne 2100-2260 cm-1
Alkene 1600-1700
34. Types of FTIR
Dispersive Infrared Spectroscopy
Utilizes diffraction grating for wavenumber
selection by using a monochromator
Fourier Transform Infrared Spectroscopy
Uses an interferometer to replace the dispersive
device and generate an interference beam that is
then exposed to the sample
42. INFRARED LIGHT SOURCE
Infrared source consist of inert solid which is
heated electrically to temperature 1500 ~ 2000oK
The continuous radiation which is emitted
resembles that of black body radiation
43. MICHELSON INTERFEROMETER
Consist of 2 plane mirrors at right angle to each
other
Beam splitter reflects 1/2 of the source intensity
to the movable mirror and transmits the other 1/2
to the fixed mirror
Spectrum
Fourier
Transform
Interferogram
Detector
45. Temperature controlled DLATGS detector
High sensitivity deuterated L-alanine triglycine
sulfate detector (DLATGS)
Maintain instrument temperature below
detector curie point (61oC)
Detector is doped with L-alanine so that
electrical field is automatically re-poled when
temperature exceeding curie point
47. MCT DETECTOR
High sensitivity
Faster response
Necessary to cool by LN2
Narrow band
48. Advantages of FTIR Vs Dispersive
Multiplex advantage (Fellgett)
Scans all wavenumbers at a time
Aperture advantage (Jacquinot)
No dispersive elements, so high throughput
Laser reference advantage (Connes)
Internal wavelength calibration
Application advantage
High speed and sensitive measurement
possible
49. Hinges using film
(4 positions)
Linkage part
Top plate (fixed)
Dynamic Alignment System
Processing circuit
He-Ne laser
Beam
splitter
Piezo actuator
Fixed mirror
Movable mirror
Sampling
circuit for
interference
condition
determination
Sensor B
Sensor A
Light source
Sample compartment
FJS system
Processing circuit
Flexible Joint
Support
50. Dynamic Alignment System
Laser light passing through the interferometer is
detected by photodiodes
Signals are generated
Difference between the result and optimum
interference condition is calculated
Result is fed back to the interferometer
The difference is eliminated by the use of a piezo
actuator
51. ADVANTAGES
Stable and prompt measurement is achieved
through dynamic alignment mechanism
To ensure that alignment of the optics is
accurate
Energy is stabilized in short time
55. Deciding Factors
Physical nature of the sample
Type of information of the sample
Limitation of a technique
56. • What is the objective of the analysis
• Background information of the sample
• Solubility of the sample
• Hardness of the sample
• Degradation of polymers
• Reactivity
What information one should have?
59. KBR pellet method
Popular method for measuring powdered samples
Suitable for hard and brittle polymers
Polymer in the form of small particles dispersed
in a disc of potassium bromide
60. Hydraulic Press and Evacuable Die
KBr discs are prepared by grinding the polymer
sample (2mg) with KBr (100-200 mg) and
compressing the whole into a transparent disc
A good spectrum will depend on whether the
sample is finely grind
Compression to a cohesive disc is done by using
an evacuable die
13mm in diameter
62. Mini-Hand Press
3mm diameter KBr pellet with briquetting frame
Hand-driven press
Small amount of sample
Simple and quick
63. Hydraulic Press Mini-hand Press
13mm in diameter KBr
pellet
3mm in diameter KBr
pellet with briquetting
frame
With hydraulic press and
vacuum pump
Hand-driven press
Takes longer time Simple and quick
High through put Low through put but
enough for FTIR
To be able to keep in
desiccator
Make each measurement
Hydraulic Press vs. Mini-Hand Press
66. Demountable cell
Qualitative analysis only
Non-volatile liquid and paste
Use spacer of 0.025 mm ~ 0.1 mm (25 µm to 100 µm )
thickness for low absorption liquid
No spacer is needed for high absorption liquid
68. Sealed liquid cell
Qualitative and quantitative analysis
Volatile and Non-volatile liquid
Use spacer of 0.025 mm ~ 0.5 mm (25 µm to 500
µm ) thickness for low absorption liquid
69. THREE CRITERIAN FOR SOLVENT
1. Sample must be soluble or miscible with the solvent
2. Solvent must not have absorption bands in the region of
interest
3. Diluent must not react with the sample
Sealed liquid cell
70. Fixed Thickness Cell
For quantitative measurement of liquid or volatile
samples
3 types of cell window
NaCl, KBr, KRS-5
Thickness
0.025mm ~ 5.0mm
71. Gas cells
For quantitative measurement of gas samples
5 cm and 10 cm pathlength.
72. Long Pathlength Gas cells
Measurement of low concentration of gas samples
1 meter and 2 meter is the pathlength
MCT detector is used
75. IR Spectra of polyester fibre with RBS 8000
Reflection Beam Condenser
76. ATR measurement
The sample is held in contact with a prism made of highly refractive index
material which transmits infrared rays.
The incident angle of IR beam is larger than the critical angle hence the IR
beam is totally reflected by the interface between sample and the prism.
Principle of ATR Measurement
Long wavelength penetrate deeper
Lower critical angle , more penetration
Penetration depth calculation
82. Acrylonitrile-butadiene rubber containing carbon black as
a reinforcement
3000 1500 400
KRS-5
Ge
Incident angle = 45o
Effect of R.I of prism
Anomalous
dispersion of
refractive index
85. Vertical Variable Angle ATR
By varying the incident angle of IR rays, the sample
profile can be studied
ATR 8000
86. Why Diamond ATR?
Diamond ATR makes up for all of the limitations of ATR
while maintaining all of the advantages
100X reduction in ATR element size allows intimate
contact with samples and greatly reduces samples by
requirement
Mechanical strength of the diamond ATR element
allows for compression of the sample for intimate
contact
Resistant to all corrosive and abrasive solvents and
samples
Cleans up easily because of the low friction
coefficient of diamond
87. DIAMOND ATR
DIAMOND ATR
1reflection Diamond ATR
DuraSamplIR
1 reflection Diamond prism1 reflection Diamond prism
contact size : about 1.5mm in diameter
contact size : about 1.5mm in diameter
Sample pressure device
88. Diffuse Reflectance
DRS method is applicable to almost all samples that can
be pulverized.
Sample preparation is easy
Specular
reflectance
lightDiffuse
reflectance light
Incident light
89. Diffuse Reflectance
To minimize the specular reflectance
Grind the sample and KBr to fine particle
Dilute the sample to 1~5% of KBr powder
Do not press the sample surface
91. Diffuse Reflectance Measurement
SiC sandpaper disk
Sample
SiC sampler is effective in sampling sample from large
forming and plastic products.
Holder can be directly attached to DRS
Emery paper is used as blank
96. Spectra of single yarn before and after compression
20um
Before
After
Diamond Compression Cell
97. Microscopy modes:
Reflectance mode (surface contaminants)
1. Reference material
2. Gold mirror
3. Aluminum coated mirror
4. Aluminum foil
Transmission mode (film, fibers)
1. Diamond cell can be used to compress the sample
for transmittance measurement
2. Put small sample on a BaF2 window