Steel is an alloy of iron and carbon. It is produced by heating iron ore and coal in a blast furnace. There are different types of steel depending on the carbon content, including mild steel (0.15-0.30% carbon), medium carbon steel (0.30-0.80% carbon), and high carbon steel (0.80-1.50% carbon). Alloy steels have additional elements added like chromium, nickel, or molybdenum to improve properties. Common alloy steels are stainless steels, heat resisting steels, and high speed steels. Cast iron is also an iron-carbon alloy but with more carbon (2-4.3%). The main types
Properties of materials
Types and applications of Ferrous and Nonferrous metals
Timber
Abrasive material
Silica
Ceramics
Glass
Graphite
Diamond
Plastic
Polymer
Properties of materials
Types and applications of Ferrous and Nonferrous metals
Timber
Abrasive material
Silica
Ceramics
Glass
Graphite
Diamond
Plastic
Polymer
This slide show accompanies the learner guide "Mechanical Technology Grade 10" by Charles Goodwin, Andre Lategan & Daniel Meyer, published by Future Managers Pty Ltd. For more information visit our website www.futuremanagers.net
This slide show accompanies the learner guide "Mechanical Technology Grade 10" by Charles Goodwin, Andre Lategan & Daniel Meyer, published by Future Managers Pty Ltd. For more information visit our website www.futuremanagers.net
important usefull engineering materials with their properties and compositionPrateek Prajapati
as the engineering materials are used in day to day life their important is to understand their functions the pictures are shown backside by their names
Engineering Materials are classified as metals , non metals.
metals are further classified as ferrous and non ferrous alloys. Nonmetals are classified as ceramics and plastics. Classification of advanced materials like composites are also discussed
Dear All, Best Greetings! This presentation is very useful to all of you to understand the steel basics, background, history, steel making process video, characteristics, metallurgical properties, iron carbon diagram, different phases in steel, effects of alloying elements, high carbon steel introduction, and application of low, medium and high carbon steel.
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.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
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 .
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.
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.
3. Fine-grained iron ore is processed into
coarse-grained clumps for use in the
blast furnace. Coal is cleaned of
impurities in a coke furnace, yielding
an almost pure form of carbon. A
mixture of iron ore and coal is then
heated in a blast furnace to produce
molten iron, or pig iron, from
which steel is made.
4.
5. Wrought iron:
Wrought iron Is a highly refined iron with a small amount of slag
forged out into fibers.
The chemical analysis of the metal shows as much as 99% of iron.
C = 0.02 – 0.03 % Si = 0.02 – 0.10 %
S = 0.008 – 0.02 % Mn = 0.00 – 0.02 %
P = 0.05 – 0.25 % Slug = 0.05 – 1.50 %
Properties:- The slag fibers in wrought iron improve strength, fatigue
and corrosion resistance of iron. It is tough, malleable and ductile.
Application:- Bolts and nuts, chains, crane hooks, Railway coupling,
pipe and fitting, sheets and boilers tubes are the main forms in which
wrought iron is used.
6. Steel:
It is an alloy of carbon and iron with carbon content usually ranges
from 0.08 to 1.5% (with 2% as a maximum possible value) .
These steels are called plain carbon steels or simply carbon steels.
Steels generally contain small amount of sulphur, phosphorous, silicon
and manganese in addition carbon.
The carbon steels can be classified on the basis of their carbon
content as
1. Low carbon steel(Mild Steel)
2. Medium carbon steel
3. High carbon steel
7. Types of Steel: (According to varying carbon
Content)
Dead Mild Steel (Less than 0.15 % carbon)
Mild Steel (0.15 – 0.30 % Carbon)
Medium Carbon (0.30 – 0.80 % carbon)
High Carbon Steel (0.80 – 1.50 % Carbon)
Cast Steel (More than 1.50 % Carbon)
8. Mild Steel or Law Carbon Steel
Ductile & malleable
More tough and more elastic than cast iron and wrought
iron
More prone to rusting than wrought iron
Corrodes quickly
Easily forged, welded & riveted
Withstands shocks & impacts well
Not much affected by saline water
Equally strong in tension, compression and in shear
Difficult to harden and temper
Sp. Gravity 7.8
9. Mild Steel : Application
Steel structure for buildings, bridge, ships, plates for boilers, tubes etc.
Used as reinforcement in R.C.C.
10. Medium Carbon Steel
Granular structure
More tough & elastic than M.S.
Easier to harden & to temper
More difficult to to forge and to weld
Stronger in compression than in tension or in shear
Withstands shocks and vibrations better
11. Medium Carbon Steel : Application
For making tools such as dills, files, chisels
Used for making those parts that ae hard , tough and durable and capable of
withstanding shocks and vibrations
Connecting rods, crane hooks, crank shafts, axles, gears, shafts, railway
wheels, railway track, etc.
12. High Carbon Steel
Increased tensile strength leads to less weight of it being
used as compared to M.S.
Structure becomes lighter
Resists corrosion better
Tougher and more elastic
More brittle and less ductile than mild steel
13. High Carbon Steel : Application
Drop hammer, dies, saws, screw drivers, cutting tools, piston rings, chisels,
etc.
14. Alloy steel
Alloy steels may be defined as steels to which elements other than
carbon are added is sufficient amounts to produce improvements in
properties.
Alloy steels can given better strength, ductility, and toughness than
plain carbon steels.
The commonly added elements added elements include nickel,
chromium, silicon, manganese, vanadium, tungsten, molybdenum,
copper, cobalt, aluminum, etc.
Main types of alloy steels used in practice are
1. Stainless steels
2. Heat resisting steels
3. High speed steels (H.S.S)
4. Spring steels
15. 1. Stainless steels
This steels are alloyed with chromium( 4 to 20%), nickel,
molybdenum, and manganese for obtaining the desired properties for
particular application.
This steels are classified into three broad categories :
a. Austenitic stainless steel
b. Ferritic stainless steel
c. Martensitic stainless steel
Application :- These steels find wide application in dairy and chemical
industries, household utensils, cutlery, and all types of surgical and
dental instruments.
16. 2. Heat resisting steels
These steels retain their properties at high temperatures for long,
periods. They possess good creep resistance, resistance to scaling
and oxidation etc.
Alloying elements, such as tungsten, chromium, and nickel are added
in order to meet these requirements.
Application :- These steels are used for gas turbines, steam, power
plants, furnace parts, etc.
17. 3. High speed steels (H.S.S)
High speed steels were so named because they may be operated as
cutting tools at much higher cutting speeds than is possible with plain
carbon tool steels.
They have excellent hardenability and can retain hardness upto 650
degree C.
The most common variety of high speed steels is 18-4-1. It contains
18%tungsten, 4% chromium, 1% vanadium and about 0.5 to 0.75%
carbon.
Application :- These steels are used for high speed cutting tools, tools
for lathe and shaping machine, drills, and milling cutters.
18. 4. Spring steels
The most suitable material for springs are those which can store up
the maximum amount of work or energy in a given weight or volume
of spring material, without permanent deformation. These steels
should have a high elastic limit as well as high deflection value.
The steels most commonly usedfor making springs are as follows :
a. Medium and high carbon steels with higher amount of manganese.
b. Medium carbon alloy steels with manganese and silicon as the main
alloying elements.
Application :- These steels are used for leaf and helical springs,
automatic and air craft valve springs etc.
19. Cast iron
Cast iron is primarily an alloy of iron and carbon. The carbon in cast
iron varies from 2% to 4.3%.
In addition to carbon, cast iron contains small amounts of silicon,
manganese, phosphorous, and sulphur.
Cast iron is the most important and widely used metal. It is very
brittle, less ductile material.
The various types of cast iron in use are as follows :
1. Grey cast iron
2. White cast iron
3. Malleable cast iron
20. 1. Grey cast iron
When carbon is presents in the form of graphite flakes, the cast iron
is called grey, because it shows grey surface on fracture.
Ordinary commercial iron having the following compositions :
Carbon = 3 to 3.5% Silicon = 1 to 2.75%
Manganese = 0.40 to 1% Phosphorus = 0.15 to 1%
Sulphur = 0.02 to 0.15%, and remaining is iron.
Properties :-
• It has a low tensile strength, high compressive strength and no
ductility.
• It can be easily machined.
• It is harder and brittle and may easily be broken if a heavy harmer is
used.
21. Application :- This iron castings are widely used for machine tool
bodies, automotive cylinder blocks, fly-wheels, pipes, and pipe
fittings, etc.
22. 2. White cast iron
White cast iron contains carbon in the form of cementite.
It shows white fractured surface due to face that it has no graphite.
It’s composition is :
Carbon = 1.75 to 2.3% Silicon = 0.85 to 1.2%
Manganese = less than 0.4% Phosphorus = less than 0.2%
Sulphur = less than 0.12%, and the remaining is iron.
Properties :-
• It is extremely hard and brittle.
• Its fractured surface has a silvery metallic appearance.
• It has excellent resistance to wear but has poor machinability.
23. Application :- This iron castings are widely used for weraring plates,
mill liners, pump liners, grinding balls etc.
24. 3. Malleable cast iron
Malleable cast iron is produced by giving long heat treatment to white
cast iron at sufficiently high temperature(900 to 950 degree C) and
then allowed to cool slowly.
Properties :-
• It is ductile and may be bent without breaking or fracturing the
section.
• The tensile strength is usually higher than that of grey cast iron and
has excellent machining qualities.
25. Application :- These castings are widely used in automotive industry. They are
also used of wagon wheels, small fitting for railway rolling stock, brake
supports, parts for agricultural machinery, door hinges etc.