Cellulose acetate is produced from cellulose sources like cotton linters, wood pulp. The cellulose is treated with chemicals to produce cellulose acetate or triacetate fibers. For manufacturing, the cellulose acetate is dissolved in acetone and forced through spinnerets into warm air to dry, forming filaments. There are two types of cellulose acetate fabrics: acetate and triacetate, which differ in their chemical composition. Cellulose acetate fibers are used to make fabrics like taffeta, satin, jersey and lace. The fabrics are resistant to mildew and moths, but can be weakened by sunlight. They are usually dry cleaned but some fabrics can be machine washed.
I am the student of Textile Institute of Pakistan in the discipline of Textile Science [B.Sc( Hons)] & this presentation is about Viscose Rayon fiber, its manufacturing, its chemical composition, its types, its modification, its identification and its uses.
I am the student of Textile Institute of Pakistan in the discipline of Textile Science [B.Sc( Hons)] & this presentation is about Viscose Rayon fiber, its manufacturing, its chemical composition, its types, its modification, its identification and its uses.
every natural fiber has unique textile property like Strength elongation and length. these properties are important for making yarn and fabric in the textile industry.
Acetate fiber under the following topics: Chemical structures monomers used, ...Amare Worku
Acetate fiber under the following topics: Chemical structures monomers used, Polymerization Process, Chemical structure of final polymer, The average molecular weight
every natural fiber has unique textile property like Strength elongation and length. these properties are important for making yarn and fabric in the textile industry.
Acetate fiber under the following topics: Chemical structures monomers used, ...Amare Worku
Acetate fiber under the following topics: Chemical structures monomers used, Polymerization Process, Chemical structure of final polymer, The average molecular weight
Production, properties and applications of cellulose acetate WebConnect Pvt Ltd
Cellulose acetate (C6H7O2(OH)3 ), basically a chain of glucose molecules, is a heavily useful industrial compound that is used in many important products used worldwidely
everyday. It is an acetate ester also known as Cellon or Rhodoid or Zyl or Zylonite. Mostly it is used as fiber material in industries.
Production Procedure of Cellulose Acetate
-Cellulose is derived from wood pulp or linters of cotton. This is not 100% pure cellulose.
Instead, it is 6-7% concentrated cellulose in water.
-In displacement and acetylation phase, firstly water or impure acetic base used to make
cellulose s.....
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.
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.
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.
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.
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 .
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
2. Introduction
The cellulose acetate are not pure cellulose compounds
like rayon.
Cellulose acetate are the acetate ester compounds of
cellulose.
The cellulose acetate fibres are of two types – Acetate
fibres and Triacetate fibres.
Acetate and Triacetate are mistakenly referred to as the
same fibre.
These fibres are similar in many of their properties but
differ in the chemical compounds.
3. Manufacturing
Raw material for acetate includes cellulose
– obtained from cotton linters, wood pulp
and chemicals.
Cellulose are shredded and mixed with
glacial acetic acid and kept aside.
It is then mixed in machine where some
chemicals are added which cellulose turns
to liquid and changes to cellulose acetate
and made into flakes.
4. Manufacturing
These flakes are dissolved in acetone.
Solution is forced through spinneret into
warm air chamber.
Here acetone evaporates and acetate
becomes hard into filament.
This method is known as dry spinning.
6. Properties of Cellulose Acetate
Dimensional stability – shape and luster
controlled by adding de lusturing agent
like titanium dioxide
Resiliency – very low resiliency so
wrinkles easily.
Moisture regain – slightly less than cotton
Effect of temperature – acetate is a
thermoplastic fiber and is easily softened
at high temperature.
7. Fabric Characteristics
Silk like appearance possesses luxurious
and soft feel.
Excellent draping qualities.
Tends to collect static electricity
Dyes well
Relatively low strength
Resistant to mildew and moths.
8. Fabric Characteristics
Weakened by sunlight
Moderately absorbent
Holds in body heat
Resistant to stretch and shrinkage
Easily blended with other fibers.
9. General Care
Usually dry cleaned. Hand wash or cool to
warm gentle machine wash can be done.
Need to be ironed at low temperature
while damp cloth on the wrong side of
fabric.
Acetone or nail polish remover damages
acetate fabric.
13. Summary
Two types of cellulose acetate fabrics –
acetate and triacetate
There are different types of yarns produced ,
which depends upon the holes of spinneret
Thick or thin yarn produced according to
spinneret
Highly absorbent and resistant to moderate
temperature
Main advantage – they don’t shrink or
wrinkle.