This document discusses nuclear fission, including its history, the fission chain reaction process, nuclear reactors, and applications. It describes how nuclear fission was discovered in 1938 and involves splitting uranium-235 atoms with neutrons, releasing energy and up to 3 neutrons to split more atoms. A self-sustaining chain reaction can occur in a nuclear reactor, where the heat generated is used to produce steam to power generators and produce electricity. Nuclear fission is applied in nuclear power plants, nuclear weapons, and medical and scientific research.
origin of quantum physics -
Inadequacy of classical mechanics and birth of QUANTUM PHYSICS
ref: Quantum mechanics: concepts and applications, N. Zettili
origin of quantum physics -
Inadequacy of classical mechanics and birth of QUANTUM PHYSICS
ref: Quantum mechanics: concepts and applications, N. Zettili
Although they are tiny, atoms have a large amount of energy holding their nuclei together. Certain isotopes of some elements can be split and will release part of their energy as heat. This splitting is called fission. The heat released in fission can be used to help generate electricity in power plants.
Contents:
Nuclear Technology.
Atom.
Nuclear Energy.
Splitting the uranium atom.
chain reaction.
Types of nuclear reaction.
Nuclear fission.
Nuclear fusion.
Where does energy comes from.
Construction & Working of Nuclear Reactors.
Nuclear Weapons.
Types of Fission Bombs.
Gun Triggered fission bombs.
Implosion Triggered fission bombs.
Hydrogen bomb & Functioning & its effects.
Advantages and Disadvantages
The Future of Nuclear Energy
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.
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.
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.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
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.
4. HISTORY:
After James Chadwick discovered the neutron in 1932.
Enrico Fermi and his colleagues in Rome studied the
results of bombarding uranium with neutrons in 1934.
Fermi concluded that his experiments had created new
elements with 93 and 94 protons, which the group
dubbed Ausonium and Hesperium respectively.
However, not all were convinced by Fermi's analysis of
his results.
5. NUCLEAR FISSION OF HEAVY ELEMENTS WAS
DISCOVERED ON DECEMBER 17, 1938 BY
GERMAN OTTO HAHN AND HIS
ASSISTANT FRITZ STRASSMANN.
Otto Hahn Fritz Strassmann
6. CONT……
Nuclear fission explained theoretically in January
1939 by Lise Meitner and her nephew Otto Robert
Frisch.
Frisch named the process by analogy with biological
fission of living cells. It is an exothermic
reaction which can release large amounts
of energy both as electromagnetic radiation and
as kinetic energy of the fragments.
8. INTRODUCTION:
Nuclear fission is either a nuclear reaction or
a radioactive decay process in which the nucleus of
an atom splits into smaller parts (lighter nuclei).
The fission process often produces
free neutrons and gamma photons, and releases a
very large amount of energy even by the energetic
standards of radioactive decay.
Fission is a form of nuclear transmutation because the
resulting fragments are not same element as the
original atom.
10. CONT……
This process may be represented by the following
nuclear equation:
92U235 + O
1n —› 56Ba141 + 36Kr92 + 3 0
1n + Q
Where Q is the energy released in this reaction.
When this is done, the amount of energy typically
released in the case of U-235 is around 200MeV
(0.00,000,000,003,204 joules).
13. INTRO:
"Chain reactions" at that time were a known
phenomenon in chemistry, but the analogous
process in nuclear physics, using neutrons, had
been foreseen as early as 1933 by Szilárd,
although Szilárd at that time had no idea with what
materials the process might be initiated. Szilárd
considered that neutrons would be ideal for such a
situation, since they lacked an electrostatic charge.
14. CHAIN REACTION:
A chain reaction is a sequence of reactions where
a reactive product or by-product causes additional
reactions to take place.
An atom of uranium-235 to undergo fission by
bombarding it with neutrons.
Along with barium and krypton, three neutrons are
released during the fission process. These neutrons
can hit further U-235 atoms and split them,
releasing yet more neutrons. This is called a chain
reaction.
16. CONT……
Although the half-life of U-235 is a very long time, if
we get enough of the atoms together in one place
the chances that any one of them will
undergo spontaneous fission is very, very high.
Additional Neutrons create a chain reaction, which
is controlled by the control rods.
Newly created fission neutrons move at about 7%
of the speed of light, and even moderated neutrons
move at about 8 times the speed of sound.
18. NUCLEAR REACTOR:
“The assembly which is used to convert heat
generated in nuclear reaction into electrical energy
is called Nuclear Reactor.”
In a reactor fission reaction produces heat.
When fission takes place in atom of uranium or any
heavy atom, then energy at the rate of 200MeV per
nucleus is produced in form of Kinetic energy of
fission fragments.
These fast moving fragments besides colliding with
one another also collide to uranium atoms.
19. CONT……
Due to collisions kinetic energy gets transformed
into heat energy.
Heat produced is used to produce steam which in
turn rotates the turbine.
As a result, turbine rotates the generator which
produces electricity.
21. WORKING OF REACTOR;
Reactor Core; cylindrical tubes in which fuel is kept.
Uranium- 92U235 is used as fuel.
The quantity of 92U235 in the naturally occurring
Uranium is 0.7%.
Fuel rods are placed in substances of small atomic
weight, such as water, heavy water, carbon etc
called moderators.
Moderator; is used to slow down the speed of
neutrons produced during the fission process to
direct them towards the fuel.
22. CONT……
Control rods; number of neutrons produced are
controlled because only one neutron has to
produce further fission reaction.
Control rods are made of cadmium or boron.
Chain reaction takes place in the core and
produces heat. Temperature rise about 500°C.
Steam is produced from this heat and is transported
with the help of water or heavy water.
Temperature of steam coming out from turbine is
about 300°C which is further cooled to produce
water again.
24. APPLICATIONS:
December 20, 1951- Electricity was generated for
the first time by a nuclear reactor – A the EBR-I
experimental station near Arco, Idaho – initially
produced about 100 kW
1956 - world's first commercial nuclear power
station in Sellafield, England – initial capacity of 50
MW (later 200 MW)
In July 1945, the first atomic explosive device,
dubbed "Trinity", was detonated in the New Mexico
desert. It was fueled by plutonium created at
Hanford.
25. IN AUGUST 1945, TWO MORE ATOMIC DEVICES –
"LITTLE BOY", A URANIUM-235 BOMB, AND "FAT
MAN", A PLUTONIUM BOMB – WERE USED AGAINST
THE JAPANESE CITIES OF HIROSHIMA AND NAGASAKI.
26. CONT……
In August 1945, two more atomic devices – "Little
Boy", a uranium-235 bomb, and "Fat Man", a
plutonium bomb – were used against the Japanese
cities of Hiroshima and Nagasaki.
These fission reactions produce new nuclides or
elements which are used in medical diagnose and
treatments and biological experimentations.
Nuclear fission reaction is used to produce energy
for nuclear power.
It causes nuclear bomb to explode.
27. ADVANTAGES & DISADVANTAGES
It produces
tremendous energy
from small amount of
nuclear fuel.
Once a fuel added a
plant can work for
years.
Does not produce
greenhouse gases like
CO2.
Difficult to dispose the
radioactive waste from
nuclear fission
reaction.
Risks of accidents in
nuclear reactors.
High cost of installation
of nuclear plants.
Advantages Disadvantages