This document discusses nuclear fission and was prepared by a group of students. It provides a brief history of nuclear fission pioneers like Otto Hahn and Enrico Fermi. It defines fission as the splitting of a heavy nucleus into smaller fragments. When uranium-235 captures a neutron, it becomes unstable uranium-236 and splits into fragments, releasing neutrons and energy in the process. This energy release can be harnessed for nuclear power generation or results in an atomic explosion depending on whether the fission reaction is controlled or uncontrolled.
Nuclear chain reaction. What is a chain reaction? Nuclear Fission process.Mechanism of the Fission process.Examples of Nuclear Fission Reaction, Fission as a chain mechanism.Critical Mass. Why we use Uranium-235 and Plutonium? Types of Fission chain process. Control Chain Reaction. Uncontrolled Chain reaction. Problem with Nuclear Fission Reactions. Advantages of the fission process. Disadvantages of the Fission process. Applications of the Fission process. A complete explanation by Syed Hammad Ali Gillani.
ADVANTAGES Nuclear power generation does emit relatively low amounts of carbon dioxide (CO2). The emissions of green house gases and therefore the contribution of nuclear power plants to global warming is therefore relatively little. This technology is readily available, it does not have to be developed first. It is possible to generate a high amount of electrical energy in one single plant
Nuclear chain reaction. What is a chain reaction? Nuclear Fission process.Mechanism of the Fission process.Examples of Nuclear Fission Reaction, Fission as a chain mechanism.Critical Mass. Why we use Uranium-235 and Plutonium? Types of Fission chain process. Control Chain Reaction. Uncontrolled Chain reaction. Problem with Nuclear Fission Reactions. Advantages of the fission process. Disadvantages of the Fission process. Applications of the Fission process. A complete explanation by Syed Hammad Ali Gillani.
ADVANTAGES Nuclear power generation does emit relatively low amounts of carbon dioxide (CO2). The emissions of green house gases and therefore the contribution of nuclear power plants to global warming is therefore relatively little. This technology is readily available, it does not have to be developed first. It is possible to generate a high amount of electrical energy in one single plant
Nuclear Energy or Nuclear power conversion TechnologyTesfaye Birara
Energy conversion is the process of changing one form of energy into another, a fundamental capability that enables modern civilization to function. It can occur in various ways, from converting the kinetic energy of wind into mechanical power through windmills to transforming solar energy into electrical energy in solar panels. This transformation is essential not just for daily usage but also for harnessing and utilizing natural resources more efficiently. In the context of rural electrification, this process plays a critical role. By converting available local energy resources into electricity, rural communities can access a stable and reliable power supply. This not only improves the quality of life but also supports economic development by powering homes, schools, businesses, and healthcare facilities. Consequently, energy conversion facilitates the broader goal of rural electrification, demonstrating the interconnection between technological innovation and societal advancement.
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.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
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.
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.
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.
2. A Brief History
• Otto Hahn:
Germany-Nobel Prize winner famous for his discovery of nuclear fission.
• Fritz Strassmann:
German chemist who, with Otto Hahn in 1938, identified barium
in the residue after bombarding uranium with neutrons.
• Enrico Fermi:
Italy-Nobel Prize winner and famous for creating the world's first
nuclear chain reaction.
3. What is Fission?
•Fission is another word for splitting.
•It means division or splitting into two or more parts.
•In general, If a heavy particle or object splits into two or
more parts or fragments it is called fission.
4. Analogy
• Nuclear Fission is similar to a liquid drop when excess
energy is added to it .
•When a liquid drop is given vibratory motion it
undergoes elongation and compression.
•When vibrations become very fast the drop splits into
two.
•Similar is the case of Uranium-235
6. Nuclear Fission
• When a nucleus(usually Uranium-235 fissions, it splits into several smaller
fragments.
• These fragments, or fission products, are about equal to half the original
mass.
• Two or three neutrons are also emitted.
• The sum of the masses of these fragments is less than the original mass.
• This 'missing' mass has been converted into energy according to Einstein's
equation.
• Fission can occur when a nucleus of a heavy atom captures a neutron, or it
can happen spontaneously.
8. Neutrons may
1 - Cause another fission by colliding with a U235 nucleus
2 - Be absorbed in other material
3 - Lost in the system
If sufficient neutrons are present, we may achieve a chain reaction
Each split (fission) is
accompanied by a large
quantity of E-N-E-R-G-Y
• Creates two smaller nuclides and free neutrons.
• The free neutrons potentially collide with nearby U235 nuclei
9. Steps In Nuclear Fission
• The 235U nucleus captures a thermal (slow-moving) neutron.
• The capture results in the formation of 236U*, and the excess
energy of this nucleus causes it to undergo violent oscillations.
• The 236U* nucleus becomes highly elongated, and the force of
repulsion between protons in the two halves of the dumbbell-
shaped nucleus tends to increase the distortion.
• The nucleus splits into two fragments, emitting several neutrons
in the process.
10. FISSION CAN BE USED
• GOOD
• A controlled chain reaction in a reactor used in nuclear power
plants to produce electricity.
• EVIL
• An uncontrolled chain reaction is used to create incredibly
powerful weapons – the atomic bombs dropped on Japan.