This document provides an overview of key concepts related to electric circuits, including:
1) Describing the differences between direct and alternating currents, and discussing challenges students face distinguishing between voltage and current.
2) Explaining how batteries supply energy to a circuit by transferring energy to charges located in circuit components like filaments, in accordance with the law of conservation of energy.
3) Discussing models used to represent circuits, including water and hill models, and how more accurate representations show batteries maintaining electric fields.
4) Defining concepts like electromotive force, potential difference, resistance, and how these relate to determining current and power in both simple and complex circuit configurations.
Physics Class X Electric Current
Contents
1 Electricity
2 Electric Current
3 Electric Potential & Potential Difference
4 Electromotive Force (emf)
5 Electric Circuit and components
6 Current and Voltage Measurements
7 OHM’s Law
8 Factors Affecting Resistance
9 Combination of Resistors(Series & Parallel)
10 Heating Effect of Electricity and its apps.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Physics Class X Electric Current
Contents
1 Electricity
2 Electric Current
3 Electric Potential & Potential Difference
4 Electromotive Force (emf)
5 Electric Circuit and components
6 Current and Voltage Measurements
7 OHM’s Law
8 Factors Affecting Resistance
9 Combination of Resistors(Series & Parallel)
10 Heating Effect of Electricity and its apps.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
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.
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/
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.
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.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
2. Learning outcomes
• describe the difference between direct and alternating currents
• apply the law of conservation of energy to simple circuits
• use concepts of electric potential energy, electromotive force and
potential difference to describe DC circuits
• predict the behaviour of resistors in series and parallel and be able to
calculate effective resistances
• recognise and use variable resistors, LDRs, LEDs, thermistors
• use the relationship between power, potential difference and current to
analyse simple circuits
• explain how fuses protect electrical appliances & calculate fuse values
• critically use a variety of models to show how energy is transferred in
simple circuits
• develop confidence with electrical equipment: use ammeters,
voltmeters and multimeters in simple circuits
3. Teaching challenges
Once students grasp the idea of an electric current,
they find it difficult to accept the need for another
measure of electricity (voltage, potential difference).
It doesn’t help that voltmeters and ammeters look so
similar.
4. Charge and current
Charge is a fundamental property (of protons and
electrons). Charge is conserved.
Current is the rate of flow of charge past a point.
I = current in A, Q = charge in C, t = time in s
Current in a wire (SPT simulations)
electron drift
conventional current
t
Q
I
t
I
Q
5. AC and DC
Direct current – always in one
direction, though flow rate
may change e.g. a pulsed
current.
Alternating current – flow
direction changes with time.
Flow rate may also change.
6. Circuits: the energy story
KS2: A battery gives electrical ‘push’ to electrons in a circuit.
KS3/4: A battery gives electrical ‘push and pull’ to electrons in a
circuit.
Better: A battery is a chemical store of energy. When connected in
a circuit, it transfers energy to a circuit component by doing work
on charges located there e.g. in a filament.
Law of conservation of energy: energy supplied = work done in
the external circuit (some always dissipated as heating).
10. Other models for circuits
In pairs, do the C21 Activity Models of electric circuits.
Supplementary powerpoint: teaching models found in
school textbooks, collected by Robin Millar, University
of York.
11. EMF and potential difference
A-level: A battery maintains an electric field through the circuit.
This enables it to do work on charges wherever there is a
potential difference e.g. in a filament.
Electromotive force is the energy supplied per unit
charge. (work done on each coulomb of charge)
Potential difference (p.d.) is the energy transferred per
unit charge between two points in a circuit .
(work done by each coulomb of charge)
Unit (for both) is the volt = joule/coulomb; 1 V = 1 J/C
12. Sources of EMF
chemical cell
dynamo
mains (dynamo at a power station)
photovoltaic cell (solar cell)
piezoelectric crystal (gaslighter)
EMFs can be added
in series
in parallel
13. Resistance
When the same p.d. is applied across different
conductors, different currents flow.
Resistance R of a conductor is defined as the ratio of
the potential difference V applied across it to the
current I flowing through it.
unit: ohm
I
V
R
14. Current, voltage and resistance
Current in a simple circuit will be larger if
• voltage of the supply is larger
• resistance in the circuit is smaller
where R is resistance, is resistivity of the material, l is its length
and A is its cross-sectional area.
The same relationships apply in networks of identical
resistors.
A
l
R
15. Resistor networks
Resistors in series
V = V1+ V2 [conservation of energy]
IR = IR1 + IR2
R = R1 + R2 R is always larger than any of R1, R2 etc
Resistors in parallel
I = I1 + I2 [conservation of charge]
V/R = V/R1 + V/R2
1/R = 1/R1 + 1/R2 R is always smaller than any of R1, R2 etc
16. Combining resistors
A practical exercise, in pairs.
Multimeter: set on resistance range.
Black lead from COM terminal
Red lead from terminal
Use breadboard to configure resistors temporarily.
NOTE: Each column of 5 holes is connected together.
17. Ohmic & non-ohmic conductors
• An ohmic conductor has a straight-line graph that
passes through the origin (I proportional to V)
• Resistance is always the ratio of V to I, not the
gradient of the I - V graph.
Ohm (1826): replaced voltaic pile with thermocouple as his source
of EMF. ‘At constant temperature, the p.d. across a conductor is
proportional to the current through it.’
18. Electrical power and fuses
Heating effect of current
(Joule, 1841, coil of wire in a jar of water)
P = IV = I2R
Fuse action:
e.g. If live wire contacts the
metal body of a kettle, the body is connected
to earth, so this produces a current surge and fuse (wire) melts,
isolating the appliance from live wire (supply).
Fuse value: Use appliance power and mains voltage to calculate its
normal current. I = P/ V Select next higher fuse rating.
Electrical fire hazard when current is too large.
19. Component characteristics
The electrical behaviour of a component is described by
its I-V graph.
For example:
I/V characteristic of a carbon resistor
I/V characteristic of a filament lamp
I/V characteristic of a semiconductor diode
20. Practical session
1. Component characteristics. Collect data and draw the
I/ V graph for resistor, lamp and diode.
2. Investigate how the resistance of LDR and thermistor
vary.
3. Experiments with SEP Energymeter
– Getting to know the joule and the watt
– Using an energymeter to measure efficiency of energy
transfer
– Using an energymeter to measure power in electrical circuits
21. Potential dividers
Useful for constructing sensors
In pairs, sketch
• a dark sensor
• a heat sensor
• a cold sensor
2
1
2
1
2
1
R
R
IR
IR
V
V
22. Electrical energy
Power is the rate of energy transfer
P = E/ t
so E = Pt = IVt
units of electrical energy: kW-hr or joules
Paying for electricity: cost per metered kW-hr
23. Problem-solving
Do any (all) of
• McDermott Physics by Inquiry Exercises
• Physics for You questions on Circuits
• TAP 109-3: Lamp and resistor in series
• Breithaupt questions from sections 13.3 Potential difference,
13.4 Resistance
Standard procedure for quantitative problems: Sketch the
circuit, write down known quantities, start with an equation in
symbols, show all working, include units with the answer.
25. In practice
Real power supplies cannot maintain their terminal
p.d. when they provide larger currents.
Explaining why this happens requires another idea.
26. Support, references
www.talkphysics.org
SPT 11-14 Electricity & Magnetism
Ep4 Getting to grips with voltage
Ep5 Electrical power: a final look
David Sang (ed, 2011) Teaching secondary physics ASE / Hodder
PhET simulations Electricity, Magnets & Circuits
Practical Physics Guidance pages e.g. Models of electric circuits