Liquid crystals are an intermediate phase of matter that exhibit properties of both liquids and crystals. They form due to certain ordering of molecules that is dependent on temperature. There are two main types - thermotropic liquid crystals, whose order depends on temperature alone, and lyotropic liquid crystals, whose order depends on both temperature and concentration in a solvent. Thermotropic crystals can form nematic, smectic or cholesteric phases with varying degrees of positional and orientational ordering. Liquid crystals find applications in LCD displays, thermometers, and battery charge indicators due to their sensitivity to temperature, electric fields, and other stimuli.
Intermediate state of mesophases & halfway between isotropic liquid &solid crystal.
In solid crystal, basic unit display translational long range order, with center of molecule located on crystal lattice &display orientational order.
In isotropic liquid, basic unit do not preset positional or orientational long rang order.
Intermediate state of mesophases & halfway between isotropic liquid &solid crystal.
In solid crystal, basic unit display translational long range order, with center of molecule located on crystal lattice &display orientational order.
In isotropic liquid, basic unit do not preset positional or orientational long rang order.
Solid State of matter,
Crystalline, Amorphous & Polymorphism Forms,
Classification of solid state of matter On the basis of Internal Structure,
PHYSICAL PHARMACEUTICS-I,
Habet,
B.Pharm,
THE PHASE RULE
phase rule
degree of freedom in mixture
one component system
two component system
pressure temperature diagram sulfur hydrogen
eutectic eutectoid mixture
I hope You all like it. I hope It is very beneficial for you all. I really thought that you all get enough knowledge from this presentation. This presentation is about materials and their classifications. After you read this presentation you knowledge is not as before.
examples of materials that have directional properties as a single cry.docxtodd401
examples of materials that have directional properties as a single crystal but are isotropic in their polycrystalline form.
Solution
Liquid crystals (LCs) are matter in a state that has properties between those of conventional liquid and those of solid crystal. [1] For instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of liquid-crystal phases, which can be distinguished by their different optical properties (such as birefringence). When viewed under a microscope using a polarized light source, different liquid crystal phases will appear to have distincttextures. The contrasting areas in the textures correspond to domains where the liquid-crystal molecules are oriented in different directions. Within a domain, however, the molecules are well ordered. LC materials may not always be in a liquid-crystal phase (just as water may turn into ice or steam).
Liquid crystals can be divided into thermotropic, lyotropic and metallotropic phases. Thermotropic and lyotropic liquid crystals consist of organic molecules. Thermotropic LCs exhibit a phase transition into the liquid-crystal phase as temperature is changed. Lyotropic LCs exhibit phase transitions as a function of both temperature and concentration of the liquid-crystal molecules in a solvent (typically water). Metallotropic LCs are composed of both organic and inorganic molecules; their liquid-crystal transition depends not only on temperature and concentration, but also on the inorganic-organic composition ratio.
Examples of liquid crystals can be found both in the natural world and in technological applications. Most contemporary electronic displays use liquid crystals. Lyotropic liquid-crystalline phases are abundant in living systems. For example, many proteins and cell membranes are liquid crystals. Other well-known examples of liquid crystals are solutions ofsoap and various related detergents, as well as the tobacco mosaic virus.
.
Solid State of matter,
Crystalline, Amorphous & Polymorphism Forms,
Classification of solid state of matter On the basis of Internal Structure,
PHYSICAL PHARMACEUTICS-I,
Habet,
B.Pharm,
THE PHASE RULE
phase rule
degree of freedom in mixture
one component system
two component system
pressure temperature diagram sulfur hydrogen
eutectic eutectoid mixture
I hope You all like it. I hope It is very beneficial for you all. I really thought that you all get enough knowledge from this presentation. This presentation is about materials and their classifications. After you read this presentation you knowledge is not as before.
examples of materials that have directional properties as a single cry.docxtodd401
examples of materials that have directional properties as a single crystal but are isotropic in their polycrystalline form.
Solution
Liquid crystals (LCs) are matter in a state that has properties between those of conventional liquid and those of solid crystal. [1] For instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of liquid-crystal phases, which can be distinguished by their different optical properties (such as birefringence). When viewed under a microscope using a polarized light source, different liquid crystal phases will appear to have distincttextures. The contrasting areas in the textures correspond to domains where the liquid-crystal molecules are oriented in different directions. Within a domain, however, the molecules are well ordered. LC materials may not always be in a liquid-crystal phase (just as water may turn into ice or steam).
Liquid crystals can be divided into thermotropic, lyotropic and metallotropic phases. Thermotropic and lyotropic liquid crystals consist of organic molecules. Thermotropic LCs exhibit a phase transition into the liquid-crystal phase as temperature is changed. Lyotropic LCs exhibit phase transitions as a function of both temperature and concentration of the liquid-crystal molecules in a solvent (typically water). Metallotropic LCs are composed of both organic and inorganic molecules; their liquid-crystal transition depends not only on temperature and concentration, but also on the inorganic-organic composition ratio.
Examples of liquid crystals can be found both in the natural world and in technological applications. Most contemporary electronic displays use liquid crystals. Lyotropic liquid-crystalline phases are abundant in living systems. For example, many proteins and cell membranes are liquid crystals. Other well-known examples of liquid crystals are solutions ofsoap and various related detergents, as well as the tobacco mosaic virus.
.
State of matter and properties of matter (Part-6)(Relative humidity, Liquid ...Ms. Pooja Bhandare
RELATIVE HUMIDITY, Humidity, Wet and Dry Hygrometer, LIQUID COMPLEX, LIQUID CRYSTALS, Types of liquid crystals, GLASSY STATES, Characteristics glassy state, Types of glassy state, What is the Glass Transition Temperature?
Liquid crystals (LCs) are a state of matter that .pdfanokhijew
Liquid crystals (LCs) are a state of matter that have properties between those of a
conventional liquid and those of a solid crystal.[1] For instance, an LC may flow like a liquid,
but its molecules may be oriented in a crystal-like way. There are many different types of LC
phases, which can be distinguished by their different optical properties (such as birefringence).
When viewed under a microscope using a polarized light source, different liquid crystal phases
will appear to have distinct textures. The contrasting areas in the textures correspond to domains
where the LC molecules are oriented in different directions. Within a domain, however, the
molecules are well ordered. LC materials may not always be in an LC phase (just as water may
turn into ice or steam). Liquid crystals can be divided into thermotropic, lyotropic and
metallotropic phases. Thermotropic and lyotropic LCs consist of organic molecules.
Thermotropic LCs exhibit a phase transition into the LC phase as temperature is changed.
Lyotropic LCs exhibit phase transitions as a function of both temperature and concentration of
the LC molecules in a solvent (typically water). Metallotropic LCs are composed of both organic
and inorganic molecules; their LC transition depends not only on temperature and concentration,
but also on the inorganic-organic composition ratio.
Solution
Liquid crystals (LCs) are a state of matter that have properties between those of a
conventional liquid and those of a solid crystal.[1] For instance, an LC may flow like a liquid,
but its molecules may be oriented in a crystal-like way. There are many different types of LC
phases, which can be distinguished by their different optical properties (such as birefringence).
When viewed under a microscope using a polarized light source, different liquid crystal phases
will appear to have distinct textures. The contrasting areas in the textures correspond to domains
where the LC molecules are oriented in different directions. Within a domain, however, the
molecules are well ordered. LC materials may not always be in an LC phase (just as water may
turn into ice or steam). Liquid crystals can be divided into thermotropic, lyotropic and
metallotropic phases. Thermotropic and lyotropic LCs consist of organic molecules.
Thermotropic LCs exhibit a phase transition into the LC phase as temperature is changed.
Lyotropic LCs exhibit phase transitions as a function of both temperature and concentration of
the LC molecules in a solvent (typically water). Metallotropic LCs are composed of both organic
and inorganic molecules; their LC transition depends not only on temperature and concentration,
but also on the inorganic-organic composition ratio..
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
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 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.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
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.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
2. States of Matter
Liquid Crystal is a Intermediate Phase in matter
Difference in various states lies in the order of matter
The order is a function of energy and hence the temperature
Different States at different temperature
3. What is Liquid Crystal?
Misogenic State or Misogen
Occurs between the crystalline solid state
and the isotropic liquid state at distinct
temperature ranges
Possess some typical properties of a
crystalline elastic solid but also have the
characteristic properties of an ordinary
viscous liquid
4. History of Liquid Crystals
Friedrich Reinitzer in 1888 noticed that cholesteryl
benzoate
Had two melting points. At 145.5 °C it melts into a
cloudy liquid till it melts down to clear liquid at
178.5 °C.
Otto Lehmann later reported seeing crystalline
structure in that cloudy liquid and so he named it liquid
crystals in 1904
5. Properties of Liquid Crystals
• Solid Like Properties: Orderly Arrangements of particles, Anisotropy (Mostly in their
optical properties)
• Liquid Like Properties: Fluidity, Viscosity, Surface Tension
• Cloudy in appearance, which means that they scatter light in much the same way as
colloids such as milk
• The anisotropy of liquid crystals causes them to exhibit birefringence
• Liquid Crystals are subject to thermal expansion
6. Types of Liquid Crystals
On the Basis of Formation
1. Thermotropic Liquid Crystals
Temperature Variant
2. Lyotropic Liquid Crystals
Solvent + Temperature Variant
7. Thermotropic Liquid Crystals
A liquid crystal is thermotropic if its order of matter is determined by
temperature change
Obtained by
• heating a crystalline solid
• cooling an isotropic liquid
8. Phases of Thermotropic LC
1.Nematic Phase
2.Smectic Phase
3.Cholestric Phase
Based on ordering of molecules there are different type of phases that appear
due to temperature changes
10. Nematic Phase
Threadlike Structure which are formally
called disclinations
Positional Ordering is absent
Translational Ordering is present
Free to Flow like isotropic liquids
Most nematics are uniaxial, The axis is
called director
Some are biaxial
Nematic Phase LC can be easily aligned
by an external magnetic or electric field
11. Smectic Phase
The molecules are arranged in layers and exhibit some correlations in their positions in
addition to the orientational ordering.
12. Smectic Phase
Positionaly Ordered in one direction
Layer structure, One Slides over another
like in Soap
found at lower temperatures than the
nematic
Unaffected by Magnetic Field
13. Types of Smectic Phases
Depending on the molecular order in layers, a number of different types of smectics have
been observed
• Smectic A
• Smectic B
• Smectic C
14. Smectic A
Molecules are aligned perpendicular to the layers, without
long-range crystalline ordering within them
15. Smectic B
There is a hexagonal crystalline order
within the layers
Most ordered among A, B and C
16. Smectic C
The preferred molecular axis is not perpendicular
to the layers, so that the phase has biaxial symmetry
17. Cholesteric Phase
This phase exhibits a twisting of the molecules perpendicular to the director, with the
molecular axis parallel to the director
18. Cholesetric Phase
• Cholesteric Phase exhibits chirality
• Long Range Orientational Order but no long range Positional
order
• The director varies throughout the medium in a regular way
even in an unstrained state
• Only chiral molecules can give rise to such a phase
19. Cholesteric Phase
• The chiral pitch, p, refers to the distance over
which the LC molecules undergo a full 360° twist
• The structure repeats itself every half-pitch
• The pitch, p, typically changes when the
temperature is altered or when other molecules
are added to the LC
20. Lyotropic Liquid Crystals
• For lyotropic liquid crystals the important controllable parameter is the concentration, rather than
temperature or pressure
• Formed by dissolving an amphiphilic mesogen in a suitable solvent
• Amphiphilic Molecule = Hydrophilic + Hydrophobic
22. Liquid Crystal Displays(LCD)
LCD is a flat electronic display panel used for visual aid. It uses Liquid Crystals to create
visual effects on screen
Important Notes for building LCD
• The Intensity of the light can be controlled at any given point by changing the
orientation of molecules in Crystal Structure
• The orientation of molecules in LC can be manipulated by changing the electric field
and magnetic field
• There are transparent materials that can conduct electricity
24. Liquid Crystal Thermometer
A liquid crystal thermometer, temperature strip or plastic strip thermometer is a type of thermometer that
contains heat-sensitive (thermochromic) liquid crystals in a plastic strip that change colour to indicate
different temperatures
Temperature changes can affect the colour of a liquid crystal, which makes them useful for temperature
measurement
• They can be used to observe that heat flows by conduction, convection, and radiation
• In medical applications they may be used to read body temperature by placing them against the
forehead
25. Charge Indicator for batteries
The principle is similar to LC thermometers
Electrical current passing through the media
generates heat.
Heat changes temperature which in turn
relative orientation of molecules in the LC.
Change in orientation causes the change in
color which is calibrated to different levels of
charge in battery.
26. Conclusion
Examples of liquid crystals can be found both in the natural world and in technological applications
Though liquid crystals are mostly known for their application in flat panel displays. their unique
properties have been used in a number of other applications, such as organic electronics
nanoparticle organization and liquid crystal colloids liquid crystal elastomer actuators, as well as
chemical and biological sensors
Though it was discovered over a century ago the works in LC are still at its peak and there will be
more to see in Future
