In this presentation:
Surface Tension
Interfacial Tension
Definition of inerfacial tension in different ways
Measurement of interfacial and surface tesion
When phases exist together, the boundary between two of them is known as interface.
When the phase is in contact with atmosphere it is termed as surface.
Surface and Interfacial tension [Part-3(a)](Measurement of Surface and Inter...Ms. Pooja Bhandare
MEASUREMENT OF SURFACE AND INTERFACIAL TENSION
Capillary Rise Method, Drop Count and Weight Method.
Wilhelmy Plate Methods ,The DuNouy Ring Method.
Capillary Rise Method: Upward force due to surface tension: Drop count and Weight method Downward Force: Drop weight method: Drop count method
INCLUDES SPREADING COEFFICIENT AND ITS THEORY AND ALSO FEW OF ITS APPLICATION IN PHARMACEUTICAL FIELD
WILL BE HELPFUL FOR B PHARMACY STUDENTS
INCLUDES HOW IT IS DERIVED AND ALSO HOW IT IS RELATED TO SPREADING OF A CREAM OR OINTMENT ON OUR SKIN
IMPORTANCE OF SPREADING COEFFICIENT
IT INCLUDES HOW A SURFACTANT MOLECULE BEING DISTRIBUTED AT A LIQUID SURFACE/INTERFACE
ALSO EXPLAINS THE STRUCTURE OF A SURFACTANT MOLECULE AND HOW IT WILL B ORIENTED IN BOTH POLAR AND NON POLAR LIQUIDS
EXPLAIN CRITICAL MICELLAR CONCENTRATION AND ITS IMPORTANCE
MICELLE FORMATION AND STRUCTURE OF MICELLE
When phases exist together, the boundary between two of them is known as interface.
When the phase is in contact with atmosphere it is termed as surface.
Surface and Interfacial tension [Part-3(a)](Measurement of Surface and Inter...Ms. Pooja Bhandare
MEASUREMENT OF SURFACE AND INTERFACIAL TENSION
Capillary Rise Method, Drop Count and Weight Method.
Wilhelmy Plate Methods ,The DuNouy Ring Method.
Capillary Rise Method: Upward force due to surface tension: Drop count and Weight method Downward Force: Drop weight method: Drop count method
INCLUDES SPREADING COEFFICIENT AND ITS THEORY AND ALSO FEW OF ITS APPLICATION IN PHARMACEUTICAL FIELD
WILL BE HELPFUL FOR B PHARMACY STUDENTS
INCLUDES HOW IT IS DERIVED AND ALSO HOW IT IS RELATED TO SPREADING OF A CREAM OR OINTMENT ON OUR SKIN
IMPORTANCE OF SPREADING COEFFICIENT
IT INCLUDES HOW A SURFACTANT MOLECULE BEING DISTRIBUTED AT A LIQUID SURFACE/INTERFACE
ALSO EXPLAINS THE STRUCTURE OF A SURFACTANT MOLECULE AND HOW IT WILL B ORIENTED IN BOTH POLAR AND NON POLAR LIQUIDS
EXPLAIN CRITICAL MICELLAR CONCENTRATION AND ITS IMPORTANCE
MICELLE FORMATION AND STRUCTURE OF MICELLE
State of matter and properties of matter (Part-2) (Latent Heat, Vapour pressu...Ms. Pooja Bhandare
Latent Heat, Vapour pressure, Factor affecting vapour pressure, Surface area, Types of molecule, Temperature and Intermolecular forces, Sublimation Critical point
Quantitative approach to the to the factor influcing solubility of drug; (Sol...Ms. Pooja Bhandare
Quantitative approach to the to the factor influcing solubility of drugs, Temperature,Nature of solvent, The boiling point of the liquids and the melting point of solids,Crystal properties:
Particle size (surface area ) of drug particles: The influence of substituent’s in molecular structures, Molecular size:
. pH :
Rheology is the science that study flow of fluids. Viscosity is the main parameter of flow. Newtonian & non newtonian are the two types of flow behavior according to newtons law of flow. non-newtonian flow can be plastic, pseudoplastic, dilatant, thixotropic, antithixotropic or rheopexy. viscosity can be determined by using various viscometers such as capillary viscometer, cup & bob viscometer, cone & plate viscometer, falling sphere viscometer, brookfield viscometer, etc. factors affeting viscosity are intrinsic, extrinsic or temperature dependence.
Surface Tension is defined as the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.
It is due to the phenomena of surface tension that the drops of water tend to assume a spherical shape to attain minimum surface area. the presentation gives a brief description of the methods to measue this important property of the interface of two fluid.
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?
SURFACE TENSION, INTERFACIAL TENSION, SURFACE FREE ENERGY, Measurement of surface and interfacial tension-capillary rise method, drop number method, drop weight method, Du Nuoy tensiometer method, Spreading of liquids, spreading coefficient, surface active agents, hydrophilic-lipophilic balance, soluble monolayers, Adsorption on solid surface, Isotherms
R. VIJAYAKUMAR., M Pharm,
Research Scholar
department of Pharmaceutical Technology.
Anna university- BIT
Tiruchirappalli
III Semester.
UNIT-IV / Micromeritics
State of matter and properties of matter (Part-2) (Latent Heat, Vapour pressu...Ms. Pooja Bhandare
Latent Heat, Vapour pressure, Factor affecting vapour pressure, Surface area, Types of molecule, Temperature and Intermolecular forces, Sublimation Critical point
Quantitative approach to the to the factor influcing solubility of drug; (Sol...Ms. Pooja Bhandare
Quantitative approach to the to the factor influcing solubility of drugs, Temperature,Nature of solvent, The boiling point of the liquids and the melting point of solids,Crystal properties:
Particle size (surface area ) of drug particles: The influence of substituent’s in molecular structures, Molecular size:
. pH :
Rheology is the science that study flow of fluids. Viscosity is the main parameter of flow. Newtonian & non newtonian are the two types of flow behavior according to newtons law of flow. non-newtonian flow can be plastic, pseudoplastic, dilatant, thixotropic, antithixotropic or rheopexy. viscosity can be determined by using various viscometers such as capillary viscometer, cup & bob viscometer, cone & plate viscometer, falling sphere viscometer, brookfield viscometer, etc. factors affeting viscosity are intrinsic, extrinsic or temperature dependence.
Surface Tension is defined as the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.
It is due to the phenomena of surface tension that the drops of water tend to assume a spherical shape to attain minimum surface area. the presentation gives a brief description of the methods to measue this important property of the interface of two fluid.
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?
SURFACE TENSION, INTERFACIAL TENSION, SURFACE FREE ENERGY, Measurement of surface and interfacial tension-capillary rise method, drop number method, drop weight method, Du Nuoy tensiometer method, Spreading of liquids, spreading coefficient, surface active agents, hydrophilic-lipophilic balance, soluble monolayers, Adsorption on solid surface, Isotherms
R. VIJAYAKUMAR., M Pharm,
Research Scholar
department of Pharmaceutical Technology.
Anna university- BIT
Tiruchirappalli
III Semester.
UNIT-IV / Micromeritics
This slides will give us a brief idea about the surface tension of a liquid. it will also describe about the importance and effect in our day to day life. determine the theory on surface tension and solve various problems on it.
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.
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
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.
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.
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.
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
2. Surface is the boundary between a solid/liquid and air/vaccum
Interface is the boundary between two or more distinct phases exist together
3. Surface tension is defined as the force per unit length parallel to the
surface to counter balance the net downward pull.
Unit: dynes/cm ergs/m N/m
4. Interfacial tension is defined as the force per unit length parallel
to the interface to counter balance the net inward pull.
In the case of interface the molecules
at the interface will be pulled by both
faces into the bulk
Since COHESIVE FORCE (between like
molecules) are stronger than
ADHESIVE FORCE (between unlike
molecules) the net pull will be into the
bulk of same phase.
5. INTERFACIAL TENSION always less than SURFACE TENSION
Adhesive force between molecules at the surface and air
molecules is negligible when compared to the adhesive force
between two immiscible liquids.
The inward pull will be opposed by the adhesive force to an extend
in the case of an interface
This is negligible in case of surfaces
So net inward pull will be more in magnitude in the case of surface.
So the counter balancing force also will be high in case of surface
when compared to interface
6. 𝐴 = 𝜋𝑟2𝐴 = 𝜋𝑟2
The soap film has two liquid-gas interfaces
F = w × a
a – acceleration due to
gravity (g)
F = γ× 2 l
γ =
𝑭
𝟐𝒍
Interfacial Tension – Force per Unit Length
7. dW = F × dS
dW = γ × 2l × dS
dW = γ × dA
2 (l × dS) = dA
γ =
𝒅𝑾
𝒅𝑨
Thus, Surface tension may be defined as surface free energy per unit area increase.
Thermodynamically a system is stable when the free energy is minimum. So systems will
try to reduce the surface free energy by contracting the surface area and attain stability.
Eg: When liquids suspended in air or immiscible liquids it assumes a minimum surface area
to volume ( spherical shape)
Interfacial Tension – Energy per Unit Area Increase
8. Interfacial Tension – Pressure difference across Curved Surface
Total Surface Free Energy E1 = ST × Total Area of
Bubble
4πr2γ
When radius decreased by dr free energy
E2 =4π(r-dr)2γ =
4πγ (r2-2 r dr+dr2)
4πγr2 - 8πγ r dr + 4πγ dr2
dr is very small when compared to r
So 4πγ dr2 can be omitted from the equation
So E2 = 4πγr2 - 8πγ r dr
9. Surface free energy change
E1 – E2 = 4πr2γ – (4πγr2 - 8πγ r dr)
= 8πγ r dr
Due to decrease in radius by dr free surface energy will
decrease by 8πγ r dr
This change will be opposed by pressure difference across
the wall of the bubble
Pressure is Force acting on Unit Area (δP = F/A)
Ie, Force is the pressure multiplied by total area
F = δP × A
F = δP × 4πr2
10. Energy change = Work done = Force × Displacement
Free Energy change due to decrease in radius by dr
W = F × dr
W = δP × 4πr2 × dr
W = E1 – E2
δP 4πr2 dr = 8πγ r dr
γ = δP r
2
As the radius of the bubble decreases pressure inside the bubble increases.
Smaller the bubble greater will be the internal pressure.
Or as surface tension decreases internal pressure in the bubble increases
11. EFFECT OF TEMPERATURE ON SURFACE
TENSION
Surface tension will be reduced when the temperature of the liquid
increased.
This is due to the thermal expansion of liquids
This continues till the temperature of the liquid reaches the CRITCAL
TEMPERATURE of the liquid
At this point Surface tension becomes zero
12. γ = γ0 [ 1 -
𝑇
𝑇 𝑐
]
𝑻 𝒄 – Critical Temperature
γ0 - Surface tension at thermodynamic zero (0 K)
15. Capillary rise occurs because of upward force due to
surface tension
Upward movement stops when this force is
counterbalanced by the downward force due to weight of
the capillary column
Surface tension at any point of circumference of
capillary tube = γ cos θ
Total upward force = 2πr γ cos θ
Counter balancing force due to weight of the column
= m g
= πr2h (ρ – ρ0) g + w
ρ – Density of Liquid
ρ0 – Density of vapour
w – Weight of liquid above meniscus
16. ρ >> ρ0
W is very negligible when compared to weight of column
Therefore Downward force due to weight of the column = πr2h ρg
At equilibrium
Upward force = Downward force
2πr γ cos θ = πr2h ρg
γ =
rhρg
2cos θ
In case of water θ is taken as 0. ie, cosθ = 1
Thus
γ = 𝟏
𝟐 rhρg
17. Precautions to be taken
Outer vessel should have larger diameter
Capillary tube should have uniform diameter through out its length
Height of the column should measure accurately
Temperature must be maintained uniform
Better to allow meniscus to fall down than allow to rise
18. Maximum Bubble Pressure Method
Mercury is allowed flow through
each capillaries
Difference in pressure when
bubbles form in sider and narrow
capillaries noted.
When radius of narrow capillary is
less than 0.01cm (r1) and wider is
greater than 0.2cm (r2) surface
tension is given by
𝛾 = 𝐴𝑃[1 + 0.67𝑟2 𝑔 𝐷
𝑃
]
A – Instrument constant
D – Density of the liquid
P – Difference in pressure
19. Drop Method
When a liquid is allowed to flow through a capillary tube it forms a drop at the tip
of the tube
It increases in size and detaches from the tip when weight of the drop just equals
the surface tension at the circumference of the tube
w = 2πrγ
γ = w
2πr
21. Drop Weight Method
1. Suck the liquid up to the mark A
2. Allow the liquid to drop from tip of the stalagmometer
3. Collect 20 – 30 drops and find out the weight
4. Find average weight of drops
γ = w
2 π r
Generally relative surface tension with respect to water is found out
γ l
γ w
=
w l
w w
22. Drop Count Method
1. Suck the liquid up to the mark A
2. Allow the liquid to drop from tip of the stalagmometer
3. Count the number of drops formed till the liquid reach mark B
γ = w
2 π r n
W(weight of total number of drops)= mg = vdg
d- density of the liquid
Generally relative surface tension with respect to water is found out
γ l
γ w
=
d l n w
d w n l
23. Precautions to be taken
Tip of pipette should have no imperfections in the outer
circumference
Drops should be formed slowly
About 20 – 30 drops should be collected to find the average weight
Temperature should be maintained constant
24. Wilhelmy Plate method
• Consist of a plate made up of platinum suspended vertically
from a beam attached to a torsion balance
• Liquid is taken in a dish and raised until it just touches bottom
of the plate
• When plate touches the surface, the surface force will drag the
plate downward
• Rotate the torsion wire and measure the force required to bring
back the plate to former position
• The force measured in torsion balance will be equal to the
surface tension around the perimeter of the plate
W = 2 (L+T) γ
γ =
W
2 (L+T)
25. Ring Detachment Method
• Torsion Balance or Du Nuoy balance consist of a
platinum ring of around 4 cm in circumference
suspended on a torsion wire attached to a scale
• Liquid is taken in a pan and position of pan is
adjusted so that the ring just touches the liquid
• Torsion wire is rotated till the ring just detached
from the surface of the liquid
• Force require to detach the ring from the surface
is obtained from the scale
• The force is proportional to surface tension
26. P = 2π(r1+r2) γ
γ = P / 2π(r1+r2)
r1 and r2 are inner and outer radius of the ring
For thin rings r1 = r2 = r
γ = P / 4πr
27. Precautions to be taken
The ring should lie in flat plane
The plane of the ring must be horizontal
Vessel containing liquid should have wider diameter
Temperature must be kept constant