Heat is a form of energy that causes particles to move faster, increasing their kinetic energy and temperature. A change of state, like melting or boiling, requires heat but does not change the temperature as the heat energy is used to overcome interparticle forces rather than increase kinetic energy. The specific heat of a substance determines how much heat is required to raise its temperature, with substances like water that have strong bonds requiring more heat than good conductors like metals.
HEAT AND TEMPERATURE (WEEK SIX FOR GRADE 8- 1ST QUARTER).pptxALVINMARCDANCEL2
Heat and energy are related concepts in the field of thermodynamics, which is the science of the relationship between heat, work, temperature, and energy. Heat is the transfer of energy between systems or bodies due to their temperature difference. Thermal energy is the energy contained within a system that is responsible for its temperature. Heat is a form of energy in transit, while temperature is a measure of energy.
HEAT AND TEMPERATURE (WEEK SIX FOR GRADE 8- 1ST QUARTER).pptxALVINMARCDANCEL2
Heat and energy are related concepts in the field of thermodynamics, which is the science of the relationship between heat, work, temperature, and energy. Heat is the transfer of energy between systems or bodies due to their temperature difference. Thermal energy is the energy contained within a system that is responsible for its temperature. Heat is a form of energy in transit, while temperature is a measure of energy.
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.
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.
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.
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.
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 .
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.
1. HEAT AND TEMPERATURE
Heat is a type of ENERGY. When absorbed by a substance, heat causes inter-particle bonds to weaken and break which leads to a
change of state (solid to liquid for example).
Heat causing a phase change is NOT sufficient to cause an increase in temperature.
Heat also causes an increase of kinetic energy (motion, friction) of the particles in a substance. This WILL cause an increase in
TEMPERATURE. Temperature is NOT energy, only a measure of KINETIC ENERGY
The reason why there is no change in temperature at a phase change is because the substance is using the heat only to change the way
the particles interact (“stick together”). There is no increase in the particle motion and hence no rise in temperature.
THERMAL ENERGY is one type of INTERNAL ENERGY possessed by an object. It is the KINETIC ENERGY component of the
object’s internal energy.
When thermal energy is transferred from a hot to a cold body, the term HEAT is used to describe the transferred energy. The hot
body will decrease in temperature and hence in thermal energy. The cold body will increase in temperature and hence in thermal energy.
Temperature Scales: The K scale is the absolute temperature scale. The lowest K temperature, 0 K, is absolute zero, the
temperature at which an object possesses no thermal energy.
The Celsius scale is based upon the melting point and boiling point of water at 1 atm pressure (0, 100o C)
K = oC + 273.13
UNITS OF HEAT ENERGY
The unit of heat energy we will use in this lesson is called the JOULE (J). Sometimes the CALORIE (cal) is used to express heat energy.
Here’s how the Joule and calorie are related:
Joule (J) – 1 joule is the amount of energy that raises the temperature of 1 gram of water by 0.239oC.
calorie (cal) – 1 calorie is the amount of heat required to change the temperature of 1 gram of water by 1oC.
1 cal = 4.184 J
2. Coefficient
of
linear
expansion:
Solids
Coefficient
of
volume
expansion:
Liquids
α =
Δl
loΔT
Δl
lo
= αΔT
alpha
is
the
coefficient
of
thermal
expansion,
which
varies
depending
upon
the
composi=on
of
the
object.
β =
ΔV
VoΔT
ΔV
Vo
= βΔT
beta
is
the
coefficient
of
volume
expansion,
which
will
again
vary
depending
upon
the
composi=on
of
the
object.
These
equa=ons
tell
you
that
the
space
an
object
occupies
depends
upon
temperature.
Liquid
expansion
is
always
measured
in
volume.
Solid
expansion
can
be
expressed
in
area
and
volume
ra=os;
the
coefficient
of
area
expansion
is
2x
the
linear
coefficient
and
the
coefficient
of
volume
expansion
is
3x
the
linear
coefficient.
3.
4. GASES
IDEAL
GASES
have
the
same
coefficient
of
volume
expansion
and
it
is
constant
at
all
temperatures.
ideal gas law: PV = nRT STP,
0o
C
and
1
atmosphere
pressure
5. HEAT CAPACITY AND SPECIFIC HEAT
What is HEAT CAPACITY AND SPECIFIC HEAT AND HOW ARE THEY RELATED?
The HEAT CAPACITY is the amount of heat required to raise the temperature of an object or substance 1oC. IT IS DEPENDENT UPON
THE MASS OF THE OBJECT.
The SPECIFIC HEAT is similar but defined for a specific amount of mass. It is the amount of heat required to raise 1 GRAM of a
substance 1oC.
THINK OF THE SPECIFIC HEAT PROPERTY LIKE THIS: IT TELLS YOU HOW MUCH HEAT A SUBSTANCE CAN ABSORB BEFORE YOU
SEE ITS TEMPERATURE GO UP.
UNITS OF SPECIFIC HEAT: J/goC
Think about this: If the value for the specific heat of a substance is low, what does that say about the nature of the substance? What if
it is high?
Substances with HIGH SPECIFIC HEAT are “stubborn” (for lack of a better word) about ABSORBING enough heat to make their
particles “wiggle” faster (KE increase). These substances ARE POOR CONDUCTORS OF HEAT.
Substances with LOW SPECIFIC HEAT don’t require as much energy to increase the KE of the particles.
These substances absorb heat energy EASILY and are GOOD CONDUCTORS OF HEAT.
WATER HAS A RELATIVELY HIGH SPECIFIC HEAT. To get water to increase its temperature, the molecules have to be able to move
faster and to accomplish this hydrogen bonding between them must be broken first. HEAT absorbed by water must break these
intermolecular forces BEFORE the water temperature can increase.
METALS HAVE LOW SPECIFIC HEAT VALUES. Metals are dense, with lots of particles packed into a small volume. This enables them to
absorb and CONDUCT (transfer) heat throughout their structure (atom to atom) readily. They DON’T STORE heat well but CONDUCT it
(transfer it) very well.
6. Changes
in
Phase
Changes
in
phase
are
dependent
upon
pressure
and
temperature
The
NORMAL
mel=ng
and
boiling
point
of
a
substance
is
the
temperature
at
which
the
phases
are
in
equilibrium
at
1
atmosphere.
The
CRITICAL
POINT
on
a
phase
diagram
is
the
temperature
and
pressure
point
beyond
which
the
gas
and
liquid
phases
are
not
dis=nct.
The
TRIPLE
POINT
on
a
phase
diagram
is
the
point
at
which
the
three
phases
co-‐exist.
7. HOW SPECIFIC HEAT IS RELATED TO HEAT exchange
Mathematically, specific heat is related to the absorbed or released heat with the following equation:
Q = mCp ΔT
Q is the heat absorbed in J (usually)
m is the mass of the object in grams (g)
Cp is the specific heat in J/goC
ΔT is the change in temperature before and after Q is exchanged
The SMALLER the specific heat value, the LARGER the temperature increase when comparing materials of the same mass
CONSIDER:
LAW
OF
HEAT
EXCHANGE:
when
heat
is
transferred
from
a
hot
to
a
cold
body,
the
amount
of
heat
received
by
the
cold
body
=
the
amount
of
heat
lost
by
the
hot
body.
HEAT
LOST
=
HEAT
GAINED
Qlost = (mCp ΔT)hot = (mCpΔT)cold = Qgain
8. CHANGES IN STATE
WHAT HAPPENS WHEN A SUBSTANCE CHANGES STATE? ENERGY MUST BE EXCHANGED WITH THE SURROUNDINGS.
THE SUBSTANCE MUST EITHER LOSE OR GAIN HEAT, DEPENDING ON THE DIRECTION OF THE PHASE CHANGE.
A SIMPLE WAY TO REMEMBER WHETHER HEAT IS LOST OR GAINED IS TO CONSIDER HOW CONDENSED
(HOW CLOSE THE PARTICLES ARE TO EACH OTHER) THE PHASE IS AFTER THE CHANGE OF STATE.
TO GO FROM A MORE CONDENSED TO A LESS CONDENSED PHASE REQUIRES A GAIN OF HEAT BY THE SUBSTANCE
(ENDOTHERMIC).
TO GO FROM A LESS CONDENSED TO A MORE CONDENSED PHASE REQUIRES THAT THE SUBSTANCE GIVE UP OR LOSE
HEAT (EXOTHERMIC).
A CHANGE IN STATE IS A PHYSICAL CHANGE.
Heat
of
fusion:
the
amount
of
heat
required
to
change
a
unit
mass
of
a
solid
into
a
liquid
without
a
change
in
temperature.
This
is
at
the
normal
mel=ng
point.
Heat
of
vaporiza=on:
the
amount
of
heat
required
to
change
a
unit
mass
of
a
liquid
into
a
gas
without
a
change
in
temperature.
This
is
at
the
normal
boiling
point.
DURING THE PHASE CHANGE, HEAT IS BEING ABSORBED BUT THE
TEMPERATURE DOES NOT CHANGE BECAUSE THE HEAT IS USED TO
“UNHINGE” THE INTERPARTICLE FORCES. THERE IS NO CHANGE IN
THE KINETIC ENERGY OF THE PARTICLES AND THEREFORE NO
TEMPERATURE CHANGE.