The document discusses various topics related to composite materials including:
1. Composites are made of two or more materials combined to take advantage of distinct properties of each material. Fibers include glass, carbon, and synthetic fibers while matrices include polymer, metal, ceramic, and carbon.
2. Nanocomposites contain at least one constituent with dimensions less than 100 nm which can improve properties at the macroscale. Common nanofillers include clays, carbon nanotubes, and silica.
3. In situ polymerization involves dispersing nanoparticles in a monomer and polymerizing to form a thermoset composite with strong interfaces between the polymer and reinforcement.
Miscibility and Thermodynamics of Polymer BlendsAbhinand Krishna
Presentation includes classification of polymer blends based on miscibility, phase diagram of polymer blends and thermodynamics polymer blends which includes Gibbs energy theory and Flory-Huggins Theory
know more about nanomaterials and its apllication in future as well as current situation, and what wil we reserch on basis of nanomaterials and carbon structure and its aplication in such futuriastic manner.
Miscibility and Thermodynamics of Polymer BlendsAbhinand Krishna
Presentation includes classification of polymer blends based on miscibility, phase diagram of polymer blends and thermodynamics polymer blends which includes Gibbs energy theory and Flory-Huggins Theory
know more about nanomaterials and its apllication in future as well as current situation, and what wil we reserch on basis of nanomaterials and carbon structure and its aplication in such futuriastic manner.
The presentation gives a brief idea about polymers,its definition,types of polymers,common examples of polymers,polymerization and its types,polymer processing and applications of polymers.
It is described about polymer/clay nanocomposites which can be abbreviated to PCNC, their preparation methods, properties and relevances, important types of polymers employed in the preparation of PCNC, montmorillonite crystal structures,
The presentation gives a brief idea about polymers,its definition,types of polymers,common examples of polymers,polymerization and its types,polymer processing and applications of polymers.
It is described about polymer/clay nanocomposites which can be abbreviated to PCNC, their preparation methods, properties and relevances, important types of polymers employed in the preparation of PCNC, montmorillonite crystal structures,
In this presentation include all the things like introduction, type, method of preparation,Formulation, Characterization, Application and Market Product.
The above Presentation discusses about the chapter polymers.Its definition, Types and important applications.It also covers about the process of bio degradation of polymers in the body.
This presentation dives into the deep realms of nano-chemistry starting from the very basics to a sufficient advanced level. Nano-chemistry has always been a very intriguing topic for most of us as we see it in movies more than frequently. If not, we at least hear some explanation about a curious event that relates directly to nano-chemistry.
Diving into the depths of those explanations related to nano-chemistry and revealing the actual facts about nano-chemistry and its related topics. We have formulated this presentation to become a crucial source of information regarding nano-chemistry and its other related terms.
It is also a study material for Basics of Chemistry subject taught during the 1st or 2nd semesters during B.E. / B.Tech degree courses.
This presentation talks about the nano composites and its applications. Les propriétés mécaniques des nanocomposites sont différentes de celles des matériaux composites traditionnels à cause d’un rapport surface/volume élevé du renfort, et de son facteur de forme important. Le renfort peut être sous forme de particules (minéraux), de feuillets (argiles exfoliées) ou de fibres (nanotubes de carbone). L’interface matrice-renfort présente une grande surface qui est typiquement un ordre de grandeur plus grand que celle dans le cas d’un matériau composite traditionnel. Cette interface implique qu'une faible quantité de renfort nanométrique peut avoir un effet observable sur les propriétés macroscopiques du composite. Par exemple, l’ajout de nanotubes de carbone améliore les conductivités électrique et thermique d’un matériau composite. D’autres types de nanoparticules peuvent conduire à l’amélioration des propriétés optiques, diélectriques, la résistance au feu, ou des propriétés mécaniques.
Also, very good science.
Hello nano composite has graphere also carbon nano tubes depends if you're looking for a 1D, 2D or 3D texture.
PPT on "Functionalization of Nanoparticles and Nanoplatelets" by Deepak rawalDeepak Rawal
Presentation on Functionalization of nanoparticles, magnetic nanoparticles, chemical funtionalization, funtionalization of carbon nanotubes and their applications. Introduction about graphite nanoplatelets.
Methods of polymerisation It is also called as Zeigler – Natta polymerisation.
Zeigler (1953) and Natta (1955) discovered that in the presence of a combination of transition metal halides like TCl4, ZnBr3 etc, with an organometallic compound like triethyl-aluminium or trimethyl-aluminium, stereospecific polymerisation can be carried out.
Combination of metal halides and organometallic compounds are called Zeigler Natta catalyst.
EFFECT OF FLAME RETARDANT ADDITIVES IN FLAME RETARDANT GRADE OF ABSArjun K Gopi
In this study the effect of flame retardants in flame retardant grade of abs is compared with natural ABS grade. ABS is a flammable material. It is easily burn with high flammability value. ABS materials without flame retardant are easily burned with a luminous yellow flame, smoking strongly and continue to burn after removal of the ignition source. So for some particular applications we are incorporating flame retardants into ABS. But the addition of flame retardants may leads to variation in properties. For that I have done several physical, thermal, and rheological tests to investigate the properties of the respective ABS grades. The results obtained was very interesting
The Internet is amazing, but overwhelming. This list of sites covers a wide array of interests, and each site listed can give you the information that you need without having to spend your valuable time searching and searching. Here are some of the most useful websites on the internet that you may not know about. These web sites, well most of them, solve at least one problem really well and they all have simple web addresses (URLs) that you can memorize.
Original Post http://www.attittudeblogger.in/2016/12/list-of-100-very-useful-websites.html
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
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 .
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.
2. Introduction to composites:
Definition:A composite material can be defined as a
macroscopic combination of two or more distinct material
having arecogenisable interphase between them.
It consist of a continuous phase & discontinuous phase.
continuous phase is called matrix & discontinuous phase is
called reinforcement, which is stronger than the
continuous phase
3. Category of fibers &matrix for
composites:
Fibers:
Natural fibers
Synthetic organic fibers
Aramid fiber
Polyethylene fiber
Synthetic inorganic fibers
Glass fibers
Alumina fibers
Boron fibers
Carbon fibers
Si C fibers
Whiskers(SiC is available in the form of whiskers, i.e., small
single crystals):A few tens of microns in length and less than
one micro in diameter.
5. Nanocomposites:
Polymer nanocomposites are also called polymer nanostructured materials.
They are materials of which composition includes at least one constituent with
dimensions less than 100 nm.
Their feature is that the nanoscale constituents can drastically improve and/or
modify properties and functionality of the macroscopic material.
A challenge in developing the nanocomposites is to make exceptional
properties (mechanical, optical, etc.) of the nanomaterials obvious at the
micro- and macroscale levels of the hosting bulk materials.
6. Nanoparticle classification:
Isodimensional or zero-dimensional; the same size in all directions;
aspect ratio is close to unity (L/D ~1). examples: spherical silica,
metallic nanoparticles, carbon black, fullerenes.
Fibrillar; examples: carbon nanotubes and cellulose nanofibrils.
Layered; examples: clay mineral and synthetic.
The most common nanofillers used (inorganic):
Clays,
Carbon nanotubes,
Carbon black,
Fumed silica,
Cellulose-based fibrils as organic nanofiller.
8. What is In Situ?
In situ is a Latin phrase which translates literally
to 'In position'.
8
9. What is In –situ technique?
Involve a chemical reaction resulting in the formation
of a very fine and thermodynamically stable
reinforcing phase within a matrix.
10. In -situ polymerization process:
Nanoparticles are dispersed in a liquid monomer or
relatively low-molecular-weight precursor as well as in
their solution.
When a homogeneous mixture is formed, initiator is added
and it is exposed to appropriate source of heat, light, etc.
The polymerization performed in situ results in the
nanocomposite.
Polymers thus synthesized are called thermoset.
11. Polymerization can be processed either within a mould cavity or
in some other in situ situation.
Thermosets are usually covalently cross-linked that does not
allow them to reshape. They can be reused by granulating and
using as a filler.
Nylon-6 was first used to develop nanocomposites by in situ
polymerziation of caprolactam monomer.
Epoxy, phenolic, bismaleimide and cyanate polymers as
thermosets are applied to manufacture nanocomposites.
12. To promote the crosslinking process, the curing of these
polymeric material usually needs the use of a hardener or
catalyst.
In a case, for example, epoxies, such cross-linkers as
amines, anhydrides, and Lewis acids are applied.
The disadvantage of use of curing agents is that they
modify the physical properties and influence the
functionality of nanocomposites.
13. Advantages :
• There is thermodynamic compatibility at the matrix-
reinforcement interface.
• Also, the reinforcement surfaces are likely to be free of
contamination~ Therefore, stronger matrix dispersion bond
can be achieved.
• Important for the preparation of insoluble and thermally
unstable polymer composites, which cannot be processed by
solution or melt processing.
• For preparation of polymer composites with high nanotube
loading, in-situ provides very good miscibility with almost any
types of polymers.
14. In -situ polymer processing:
• In-situ polymerization methods used to fabricate CNT-
PMMA composites by incorporating CNTs during the
course of polymerization of MMA.
• Basic starting materials:
1. Nanotubes
2. MMA monomer
• Method: In-situ free radical polymerization method
involves polymerization of monomer using a radical
initiator such as 2.2´-azobisisobutyronitrile (AIBN).
• CNTs are dispersed through ultrasonication in the
prepolymer.
15. Adding CNT at prepolymer provides good dispersion in
the low viscosity of the prepolymer.
As the polymerization progresses, the viscosity of the
solution increases and the polymer grows and wraps
around the dispersed CNTs.
Benefits:
a) Higher interfacial strengths as CNTs interact with the
growing polymer, thus forming stronger CNT-polymer
bonds via non-covalent or covalent interactions.
b) Composites with enhanced mechanical, electrical
and tribological were obtained.
16. Ingot Metallurgy
(Synthesis of composites)
Al (99.9%) +
Ti (99.7%)
Graphite powder
(40-50 μm)
Heated
1100 °C – 1200°C
1h
1300 °C – 1400°C
10 minutes
Mixture direct chill
cast into ingot bars
Melt in
graphite-lined
induction
furnace with
argon gas flow.
16
19. PMMA/GO COMPOSITE:
• The method for achieving controlled dispersion of graphene
oxide(GO) , in PMMA via the precipitation polymerisation
process in a water/methanol mixture.
• GO act as surfactant and adsorbs on the interface between
polymerised PMMA particles and solvent mixture.
• SEM confirmed that the precipitate consist of particles
surrounded by the GO sheets. Compression molding of the
precipitate yields a polymer nano composite with GO organized
into a regularly spaced 3D network which percolates at 0.2 wt %
GO.