Nitric acid is a colourless liquid most commonly manufactured by Ostwald process which converts ammonia to nitric acid, nitric acid used for fertilizers, dye intermediates, explosives
Sulfuric acid production by contact method (traditional)Mohsen Kianpour
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Manufacturing of sodium carbonate using solvay processrita martin
Solvay Process majorly used in sodium carbonate industrial production was discovered by belgian industrial chemist Ernest Solvay which uses three readily available materials salt brine, limestone, ammonia
Sulfuric acid production by contact method (traditional)Mohsen Kianpour
In this slides is about Sulfuric acid production by contact method that is a traditional method to produce sulfuric acid and more about sulfur burning models. In addition you can find more different and new processes to produce it.
Manufacturing of sodium carbonate using solvay processrita martin
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Corrosion Technology Forum – A two-day conclave discusses about corrosion prevention opportunities in the four major industries across geographies. Discusses various issues related to corrosion control, mitigation and methodologies to assess the damage due to corrosion.
Get 15% off on subscription now!! Chemical today magazine is a book for chemistry or chemical industry professionals which covers all influential topics, exotic concept &, fantastic appearance has attracted tons of readers over the globe.
Since the beginning of history recorded, human beings have sought to mask or augment their own body odor by applying perfume, which imitates nature’s pleasant smells. Many natural and man-made materials have been utilized or extracted to make perfumes. No perfume smells
Distillation is a method that can be utilized to take out an unadulterated liquid from a combination of liquids. It works when the liquids have distinguished boiling points. Distillation is typically used to detach ethanol, which is the alcohol in alcoholic drinks - from water.
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Zinc designated with the chemical symbol of Zn and an atomic number of 30. The number of electrons per shell is 2, 8, 18 and 2. The two valence electrons of zinc are in charge of shaping bonds with different atoms, which is determined by its electron affinity, electro-negativity and ionization energies.
Toluene Biodegration Using Jet Loop Reactorrita martin
Toluene aromatic hydrocarbon solvent is a solvent in paints, lacquers, thinners, glues, correction fluid, carbon nanotubes and nail polish remover used as an octane booster in gasoline fuels
AIDS stands for: Acquired Immunodeficiency Syndrome HIV stands for: Human immunodeficiency virus AIDS is a disease of the human immune system caused by the HIV
Why the statue of liberty is colored blue greenrita martin
Statue of Liberty is its own special colour because of its unique environmental conditions. It's not a simple single reaction between copper and oxygen to generate a green oxide, like you may think. The copper oxide continues to react to make copper carbonates, copper sulphide, and copper sulphate.
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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 .
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Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Richard's entangled aventures in wonderlandRichard 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.
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.
1. A R T I C L E W R I T T E N A N D P U B L I S H E D
B Y
W W W . W O R L D O F C H E M I C A L S . C O M
Manufacturing nitric acid by
Ostwald process
3. Introduction
Nitric acid is a colourless liquid that is used in the
manufacture of inorganic and organic nitrates and
nitro compounds for fertilizers, dye intermediates,
explosives, and many different organic chemicals.
Nitric acid is most commonly manufactured by
Ostwald process.
4. Steps involved in Ostwald process
Ostwald process converts ammonia to nitric acid and
involves two steps.
In step 1, ammonia is oxidized to form nitric oxide and
also nitrogen dioxide. Then in step 2, the nitrogen
dioxide that was formed is absorbed in water. This in-
turn forms nitric acid.
The Ostwald process has many well-known uses in both
the industrial and health field. Through the Ostwald
process, nitric acid is commonly used in fertilizers and
pharmaceuticals, and because of it’s chemical reaction
with some compounds it is used in rocket fuel and
explosives like trinitrotoluene (TNT).
5. Step 1 - Ostwald process
Step 1 - Primary oxidation (formation of nitric acid)
Oxidation of ammonia is carried out in a catalyst
chamber in which one part of ammonia and eight parts of
oxygen by volume are introduced. The temperature of
chamber is about 600oC. This chamber contains a
platinum gauze which serves as catalyst.
Oxidization of ammonia is reversible and exothermic
process. Therefore according to Le- chatelier’s principle,
a decrease in temperature favours reaction in forward
direction. In primary oxidization 95 per cent of ammonia
is converted into nitric oxide (NO).
4NH3 + 5O2 ↔ 4NO + 6H2O ?H -24.8 Kcal/mol
6. Step 2 - Ostwald process
Step 2 - Secondary oxidation (formation of nitrogen
dioxide)
Nitric oxide gas obtained by the oxidation of
ammonia is very hot. In order to reduce its
temperature, it is passed through a heat exchanger
where the temperature of nitric oxide is reduces to
150oC. Nitric oxide after cooling is transferred to
another oxidizing tower where at about 50oC it is
oxidized to nitrogen dioxide (NO2).
2NO + O2 ↔2 NO2
7. Step 3 - Ostwald process
Step 3 - Absorption of NO2 (formation of HNO3)
Nitrogen dioxide from secondary oxidation chamber
is introduced into a special absorption tower.
NO2 gas passed through the tower and water is
showered over it. By the absorption, nitric acid is
obtained.
3NO2 + H2O -> 2HNO3 + NO
Nitric acid so obtain is very dilute. It is recycled in
absorption tower so that more and more NO2 get
absorbed. HNO3 after recycle becomes about 68 per
cent concentrated.
8. Step 4 - Ostwald process
Step 4 - Concentration
In order to increase the concentration of HNO3,
vapours of HNO3 are passed over concentrated
H2SO4. Being a dehydrating agent, H2SO4 absorbs
water from HNO3and concentrated HNO3 is
obtained.