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ENCYCLOPEDIA -Volume 3
1. M
Maltose
Maltose (/ˈmɔˈltoʊs/
or also known
asmaltobiose or malt
sugar, is
a disaccharide formed
from two units
of glucose joined
with an α(1→4) bond,
formed from
a condensation
reaction.
The isomerisomaltose has two glucose molecules
linked
through an α(1→6) bond. Maltose is the second member of an
important biochemical series of glucose chains. Maltose is the
disaccharide produced when amylase breaks downstarch. It is
found in germinating seeds such as barley as they break down
their starch stores to use for food. It is also produced when
glucose is caramelized. Maltose was discovered by
Ireland's Cornelius O’Sullivanin 1872[5] and its name comes from
malt, from Old English mealt, of Germanic origin, and the suffix
–ose, a suffix forming names of sugars and other carbohydrates.
Maltose
α-Maltose
2. Maltose is a biomolecule that belongs to the group of
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carbohydrates within the division into three groups, which are
divided into essential elements: carbohydrates, lipids
and proteins. Carbohydrates are composed by O, H, C, and are
defined as polyhydroxyaldehydes or polyhydroxyketones.
It is generally divided into monosaccharides, oligosaccharides
and polysaccharides depending on the number of residues.
Maltose is a disaccharide formed by the union of
two glucose units (monosaccharide). The two are classified
as hexoses because each one is composed of six carbons. The two
glucoses which compose maltose are cyclized in piran form and
are joined by an O-glycosidic bond through one of the
firstglucose carbon and fourth carbon of the second glucose,
indicated as (1 → 4). The link is characterized as α due to the
-OH position of the anomeric carbon in the opposite plane of
CH2OH radical (the carbon is the number 6).Due to O-glycosidic
link, maltose is a disaccharide that can reduce Fehling's
reagent. Furthermore, maltose can be obtained
by hydrolysis of glycogen or starch, polymers of linked maltoses
in position α (1 → 4) and branching in position α (1 → 6). These
are very abundant and form a large number of branches.
Amylase enzymes produce maltose and limit dextrin. These can be
further degraded by maltase enzyme to hydrolyze maltoses as
glucoses and they are ready to be degrade and obtain energy in
form of ATP.
Maltose has the ability to reduce the Fehling’s solution, due to
its free aldehyde. The aldehyde group is oxidized giving a
positive result, which means that the maltose is a reducing
sugar. Maltose in aqueous solution exhibit mutarotation, due to
its anomeric carbon which can form α and β isomers. In aqueous
solution, it is shown a balanced way between α and β forms. It
has a sweet taste. Lu and Sharkey – in 2006 – said that maltose
was the main carbon form exported from chloroplasts at night.
MANTLE
3. The mantle is a part of a terrestrial planet or other rocky body
large enough to have differentiation by density. The interior of
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the Earth, similar to the other terrestrial planets, is
chemically divided into layers. The mantle is a layer between
the crust and the outer core. Earth's mantle is a silicate rocky
shell about 2,900 km (1,800 mi) thick that constitutes about 84%
of Earth's volume. It is predominantly solid but in geological
time it behaves like very viscous liquid. The mantle encloses
the hot core rich in iron and nickel, which occupies about 15%
of Earth's volume.
Past episodes of melting and volcanism at the shallower levels
of the mantle have produced a thin crust of crystallized melt
products near the surface, upon which we live.[4]
Information
about structure and composition of the mantle either result from
geophysical investigation or from direct geoscientific analyses
on Earth mantle derived xenoliths and on mantle exposed by mid-
oceanic ridge spreading.
The Structure of the Earth
4. Two main zones are distinguished in the upper mantle: the
inner asthenosphere composed of plastic flowing rock about 200 km
thick,and the lowermost part of the lithosphere composed of
rigid rock about 50 to 120 km thick. A thin crust, the upper
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part of the lithosphere, surrounds the mantle and is about 5 to
75 km thick.
In some places under the ocean the mantle is actually exposed on
the surface of the Earth. There are also a few places on land
where mantle rock has been pushed to the surface by tectonic
activity, most notably the Tablelands region of Gros Morne
National Park in the Canadian province of Newfoundland.
The mantle is divided into sections which are based upon results
from seismology. These layers (and their thicknesses/depths) are
the following: the upper mantle (starting at the Moho, or base
of the crust around 7 to 35 km downward to 410 km),the
transition zone (410–660 km), the lower mantle (660–2891 km),
and anomalous core–mantle boundary with a variable thickness (on
average ~200 km thick).
The top of the mantle is defined by a sudden increase in seismic
velocity, which was first noted by Andrija Mohorovičić in 1909;
this boundary is now referred to as the "Mohorovičić
discontinuity" or "Moho". The uppermost mantle plus overlying
crust are relatively rigid and form the lithosphere, an
irregular layer with a maximum thickness of perhaps 200 km,
below the lithosphere the upper mantle becomes notably more
plastic. In some regions below the lithosphere, the seismic
velocity is reduced; this so-called low-velocity zone (LVZ)
extends down to a depth of several hundred km.
Inge Lehmann discovered a seismic discontinuity at about 220 km
depth; although this discontinuity has been found in other
studies, it is not known whether the discontinuity is
ubiquitous. The transition zone is an area of great complexity;
it physically separates the upper and lower mantle. Very little
is known about the lower mantle apart from that it appears to be
relatively seismically homogeneous. The D" layers at the core–
mantle boundary separates the mantle from the core.
MOMENTUM
5. In classical
mechanics, line
ar momentum or
translational
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momentum (pl. m
omenta; SI unit
kg m/s, or
equivalently, N
s) is the
product of the
mass and veloci
ty of an
object. For
example, a
heavy truck moving fast has a large momentum—it takes a large
and prolonged force to get the truck up to this speed, and
it takes a large and prolonged force to bring it to a stop
afterwards. If the truck were lighter or moving more slowly,
then it would
have less
momentum.
Like velocity, linear momentum is a vector quantity, possessing
a direction as well as a magnitude: Linear momentum is
also a conserved quantity, meaning that if a closed system is
not affected by external forces, its total linear momentum
cannot change. In classical mechanics, conservation of linear
momentum is implied by Newton's laws; but it also holds
in special relativity (with a modified formula) and, with
appropriate definitions, a (generalized) linear momentum
conservation law holds in electrodynamics, mechanics, quantum,
and general relativity.
Momentum has a direction as well as magnitude. Quantities that
have both a magnitude and a direction are known as vector
quantities. Because momentum has a direction, it can be used to
predict the resulting direction of objects after they collide,
as well as their speeds. Below, the basic properties of momentum
are described in one dimension. The vector equations are almost
identical to the scalar equations (see multiple dimensions).
Billiard balls possesses momentum.
6. 95
MUDSLIDE
A mudslide is the most rapid (up to 80 km/h, or 50 mph) and
fluid type of downhill mass wasting. It is a rapid movement of a
large mass of mud formed from loose dirt and water. Similar
phenomena include mudflow, mud stream, debris flow (e.g. in
high mountains), jökulhlaup, and lahar (from volcanoes). These
terms cover a broad variety in water content (from loamy mud, to
almost liquid, and even steam); material (wet
soil, sandy sediments and/or silt, dirt, rock, debris, volcanic
ash, small plants, and even trees); length; total mass;
and velocity.
Heavy rainfall, snowmelt, or high levels of water flowing
through cracked bedrock may trigger a movement of soil or
sediments. Floods, debris- and mud flows may also occur when
strong rains on hill or mountain slopes cause
extensive erosion and/or what is known as "channel scour". The
2006 Sidoarjo mud flow may have been caused by rogue drilling.
Some broad mudflows are rather viscous and therefore slow;
others begin very quickly and continue like an avalanche. If
Mailbox caught in a mudslide
7. large enough they can devastate villages and country sides. They
are composed of at least 50% silt and clay-sized materials and
up to 30% water. Mudflows are common even in
96
the hills around Los Angeles where they have destroyed many
homes built on hillsides without sufficient support.
The point where a muddy material begins to flow depends on
its grain and the water content. Fine grainy material or soil
has a smaller friction angle than a coarse sediment or
a debris flow, but falling rock pieces can trigger a material
flow, too. On December 14, 1999 in Vargas, Venezuela, a mudslide
known as The Vargas tragedy, which significantly altered more
than 60 kilometers (37 mi) of its coastline, was triggered due
to heavy rainfall and caused estimated damages of USD $1.79 to
$3.5 billion, a death toll considered to be between 10,000 and
30,000, 85,000 people evacuated and led to the complete collapse
of the state's infrastructure.
When a mudslide occurs it is given four named areas, the 'main
scarp', in bigger mudslides the 'upper and lower shelves' and
the 'toe'. The main scarp will be the original area of
incidence; the toe is the last affected area(s). The upper and
lower shelves are located wherever a large dip (due to mountain
or natural drop) in the mudslides path. Due to this a mudslide
can have many shelves.
Myelin
Myelin is a dielectric(electrically insulating) material that
forms a layer, the myelin sheath, usually around only
the axon of a neuron. It is essential for the proper functioning
of the nervous system. It is an outgrowth of a type of glial
cell. The production of the myelin sheath is called myelination.
In humans, the production of myelin begins in the 14th week of
fetal development, although little myelin exists in the brain at
the time of birth. During infancy, myelination occurs quickly
and continues through the adolescent stages of life.
Schwann cells supply the myelin for peripheral neurons,
whereas oligodendrocytes, specifically of the inter fascicular
8. type, myelinate the axons of have also arisen by parallel
evolution in some invertebrates, although they are quite
97
different from vertebrate myelin at the molecular level. Myelin
was discovered in 1854 by Rudolf Virchow.
Myelin is made up by different cell types, and varies in
chemical composition and configuration, but performs the same
insulating function. Myelinated axons are white in appearance,
hence the "white matter" of the brain. The fat helps to insulate
the axons from electrically charged atoms and molecules. These
charged particles (ions) are found in the fluid surrounding the
entire nervous system. Under a microscope, myelin looks like
strings of sausages. Myelin is also a part of the maturation
process leading to a child's fast development, including
crawling and walking in the first year.
Myelin is about 40% water; the dry mass is about 70–
85% lipids and about 15–30% proteins. Some of the proteins
are myelin basic protein, myelin oligodendrocyte glycoprotein,
and proteolipid protein. The primary lipid of myelin is
a glycolipid called galactocerebroside. The intertwining
hydrocarbon chains of sphingomyelin serve to strengthen the
myelin sheath.
Myelin Sheath Formation
9. The main purpose of a myelin layer (or sheath) is to increase
the speed at which impulses propagate along the myelinated
fiber.
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N
Appearance and Properties of Neon
cColorless gas exhibiting an orange-red glow
when placed in a high voltage electric field
Spectral lines of neon in the visible region
General properties
Name, symbol, number neon, Ne, 10
Pronunciation /ˈniˈɒn/
Element category noble gases
Group, period, block
18 (noble gases), 2,
p
Standard atomic weight 20.1797(6)
Electron configuration
[He] 2s2
2p6
2, 8
Atomic properties
Oxidation states 1[6]
, 0
Ionization energies
(more)
1st: 2080.7 kJ·mol−1
2nd: 3952.3 kJ·mol−1
10. Neon
Neon is a chemical element with symbol Ne and atomic number 10.
It is in group 18 (noble gases) of the periodic table. Neon is a
colorless, odorless, inert monatomic gas under standard
conditions, with about two-thirds the density of air.
It was discovered (along with krypton and xenon) in 1898 as one
of the three residual rare inert elements remaining in dry air,
after nitrogen, oxygen, argon and
carbon dioxide are removed.
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Neon was the second of these three
rare gases to be discovered, and was
immediately recognized as a new
element from its bright red emission
spectrum. The name neon is derived
from the Greek word, νέον, neuter
singular form of νέος [neos], meaning new. Neon is chemically
inert and forms no uncharged chemical compounds.
Neon is a very common element in the universe and solar system
(it is fifth in cosmic abundance after hydrogen, helium, oxygen
and carbon), but, it is very rare on Earth.
Neon gives a distinct reddish-orange glow when used in either
low-voltage neon glow lamps or in high-voltage discharge tubes
or neon advertising signs. Neon is used in a few plasma tube and
refrigerant applications but has few other commercial uses.
Newton, Isaac
Sir Isaac Newton (25 December 1642 – 20
March 1727) was an English physicist and
mathematician who is widely regarded as
one of the most influential scientists
3rd: 6122 kJ·mol−1
Covalent radius 58 pm
Van der Waals radius 154 pm
Chemical Symbol of Neon
11. of all time and as a key figure in the scientific revolution.
His book Philosophiæ Naturalis Principia Mathematica
("Mathematical Principles of Natural Philosophy"), first
published in 1687, laid the foundations for most of classical
mechanics.
Newton also made seminal contributions to optics and shares
credit with Gottfried Leibniz for the invention of
the infinitesimal calculus.
Newton's Principia formulated the laws of motion
and universal gravitation that dominated scientists' view of the
physical universe for the next three centuries. It also
demonstrated that the motion of objects on the Earth and that of
celestial bodies
100
could be described by the same principles.
Newton built the first practical reflecting telescope and
developed a theory of colour based on the observation that a
prism decomposes white light into the many colours of the
visible spectrum. He also formulated an empirical law of cooling
and studied the speed of sound.
Appearance and Properties of
Neptunium
Silvery-metallic
General properties
Name, symbol,
number
neptunium, Np, 93
Element
category
actinide
Godfrey Kneller's 1689
portrait of Isaac Newton
(age 46)
12. Neptunium
Neptunium is a chemical
element with the symbol Np
and atomic number 93. A
radioactive actinide metal,
neptunium is the first
transuranic element. Its
position in the periodic
table just after uranium,
named after the planet
Uranus, led to its being
named after Neptune, the next
planet beyond Uranus. A neptunium atom has 93 protons and 93
electrons, of which seven are valence electrons. Neptunium metal
is silvery and tarnishes when exposed to air. The element
normally exhibits five oxidation states, ranging from +3 to +7.
In the 1870s, Dmitri Mendeleev first predicted the existence of
neptunium, and many false claims of its discovery were made over
the years. Most neptunium is produced by bombarding uranium with
neutrons in
101
nuclear reactors; neptunium is also generated as a by-product in
conventional nuclear reactors.
Group, period,
block
n/a, 7, f
Standard atomic
weight
(237)
Electron
configuration
[Rn] 5f4
6d1
7s2
2, 8, 18, 32, 22, 9, 2
Discovery
Edwin McMillan and
Philip H. Abelson (1940)
Physical
properties
Density (near
r.t.)
(alpha) 20.45[1]
g·cm−3
Density (near
r.t.)
(accepted standard
value) 19.38 g·cm−3
Melting point 912 K1182 °F 639 °C, ,
Boiling point
7545 4174 °C, 4447 K,
(extrapolated) °F
Appearance and Properties of
Neodymiun
Silvery-white
13. Neodymium
Neodymium is a chemical element
with the symbol Nd and atomic
number 60. It is a soft silvery
metal that tarnishes in air.
Neodymium was discovered in 1885
by the Austrian chemist Carl Auer
von Welsbach. It is present in
significant quantities in the ore
minerals monazite and bastnäsite.
Neodymium is not found naturally
in metallic form or unmixed with
other lanthanides, and it is
usually refined for general use.
Although neodymium is classed as
a "rare earth", it is a fairly
common element, no rarer than
cobalt, nickel, and copper, and
is widely distributed in the
Earth's crust.
Neodymium compounds were first
commercially used as glass dyes
in 1927, and they remain a
popular additive in glasses. The
color of neodymium compounds—due
to the Nd3+
ion—is often a
reddish-purple but it changes
with the type of lighting, with
the type of lighting,
duefluorescent effects.
Some neodymium-doped glasses are also used in lasers that emit
infrared light with wavelengths between 1047 and 1062
nanometers.
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These have been used in extremely high power applications, such
as experiments in inertial confinement fusion.Neodymium is also
used with various other substrate crystals, such as yttrium
General properties
Name, symbol,
number
neodymium, Nd, 60
Element category lanthanide
Group, period,
block
n/a, 6, f
Standard atomic
weight
144.242
Electron
configuration
[Xe] 4f4
6s2
2, 8, 18, 22, 8,
2
Discovery
Carl Auer von
Welsbach (1885)
Physical properties
Phase solid
Liquid density
at m.p.
6.89 g·cm−3
Melting point
1297 K1875 °F
1024 °C, ,
Boiling point
5565 °F 3074 °C,
3347 K,
Heat of fusion 7.14 kJ·mol−1
14. aluminum garnet in the Nd:YAG laser. This laser usually emits
infrared waves at a wavelength of about 1064 nanometers.
Niobium
Niobium,formerly columbium, is
a chemical element with the
symbol Nb (formerly Cb) and
atomic number 41. It is a
soft, grey, ductile transition
metal, which is often found in
the pyrochlore mineral, the
main commercial source for
niobium, and columbite. The
name comes from Greek
mythology: Niobe, daughter of
Tantalus.
The English chemist Charles
Hatchett reported a new
element similar to tantalum in
1801 and named it columbium.
In 1809, the English chemist
William Hyde Wollaston wrongly
concluded that tantalum and
columbium were identical. The
German chemist Heinrich Rose
determined in 1846 that
tantalum ores contain a second
element, which he named
niobium. In 1864 and 1865, a
series of scientific findings
clarified that niobium and
columbium were the same
103
element (as distinguished from tantalum), and for a century both
names were used interchangeably. Niobium was officially adopted
Appearance and Properties of
Niobium
gray metallic, bluish when
oxidized
General properties
Name, symbol, number niobium, Nb, 41
Element category transition metal
Group, period, block 5, 5, d
Standard atomic
weight
92.90637(2)
Electron
configuration
[Kr] 4d4
5s1
2, 8, 18, 12, 1
Physical properties
Phase solid
Density (near r.t.) 8.57 g·cm−3
Melting point
2750 K4491 °F
2477 °C, ,
Boiling point
8571 °F 4744 °C,
5017 K,
Heat of fusion 30 kJ·mol−1
Heat of vaporization 689.9 kJ·mol−1
Molar heat capacity 24.60 J·mol−1
·K−1
15. as the name of the element in 1949, but the name columbium
remains in current use in metallurgy in the United States.
Brazil is the leading producer of niobium and ferroniobium, an
alloy of niobium and iron. Niobium is used mostly in alloys, the
largest part in special steel such as that used in gas
pipelines.
104
16. O
Ocean
An ocean (from Ancient Greek
Ὠκεανός (Okeanos); the World
Ocean of classical
antiquity[1]
) is a body of
saline water that composes
much of a planet's
hydrosphere. On Earth, an
ocean is one or all of the
major divisions of the
planet's World Ocean – which
are, in descending order of
area, the Pacific, Atlantic, Indian, Southern (Antarctic), and
Arctic Oceans. The word sea is often used interchangeably with
"ocean" in American English
but, strictly speaking, a
sea is a body of saline
water (generally a division of the World Ocean) that land partly
or fully encloses.
Earth is the only planet that is known to have an ocean (or any
large amounts of open liquid water). Saline water covers
approximately 72% of the planet's surface (~3.6x108
km2
) and is
Representation of ocean.
17. customarily divided into several principal oceans and smaller
seas, with the ocean covering approximately 71% of the Earth's
105
surface. The ocean contains 97% of the Earth's water, and
oceanographers have stated that only 5% of the World Ocean has
been explored. The total volume is approximately 1.3 billion
cubic kilometres (310 million cu mi) with an average depth of
3,682 metres (12,080 ft).The ocean principally comprises Earth's
hydrosphere and therefore is integral to all known life, forms
part of the carbon cycle, and influences climate and weather
patterns. It is the habitat of 230,000 known species, although
much of the ocean's depths remain unexplored, and over two
million marine species are estimated to exist. The origin of
Earth's oceans remains unknown; oceans are believed to have
formed in the Hadean period and may have been the impetus for
the emergence of life.
Ohm’s Law
Ohm's law states that
the current through a
conductor between two
points is
directly proportional to
the potential
difference across the two
points. Introducing the
constant of
proportionality,
the resistance, one
arrives at the usual
mathematical equation
that describes this
relationship: where I is the current through the
conductor in units of amperes, V is the potential difference
measured across the conductor in units ofvolts, and R is
the resistance of the conductor in units of ohms. More
specifically, Ohm's law states that the R in this relation is
V, I, and R, the parameters of Ohm's law.
18. constant, independent of the current. The law was named after
the German physicist Georg Ohm, who, in a treatise published in
1827, described measurements of applied voltage and current
106
through simple electrical circuits containing various lengths of
wire. He presented a slightly more complex equation than the one
above (see History section below) to explain his experimental
results. The above equation is the modern form of Ohm's law.
In physics, the term Ohm's law is also used to refer to various
generalizations of the law originally formulated by Ohm. The
simplest example of this is:
where J is the current density at a given location
in a resistive material, E is the electric field at that
location, and σ is a material dependent parameter called
the conductivity. This reformulation of Ohm's law is due
to Gustav Kirchhoff.
Onnes,Heike Kamerlingh
Heike Kamerlingh Onnes (21 September
1853 – 21 February 1926) was a
Dutch physicist and Nobel laureate
pioneered refrigeration techniques
and used these to explore how
materials behave when cooled to
nearly absolute zero. He was the
first toliquefy helium. His
production of extreme cryogenic
temperatures led to his discovery
of superconductivity in 1911: for
certain materials, electrical
resistance abruptly vanishes at very
low temperatures.
Kamerlingh Onnes was born in Groningen, Netherlands. His father,
Harm Kamerlingh Onnes, was a brickworks owner. His mother was
Anna Gerdina Coers of Arnhem.
In 1870, Kamerlingh Onnes attended
Heike Kamerlingh Onnes
19. the University of Groningen. He studied under Robert
Bunsen and Gustav Kirchhoff at
107
The University of Heidelberg from 1871 to 1873. Again at
Groningen, he obtained his masters in 1878 and a doctorate in
1879. His thesis was "Nieuwe bewijzen voor de aswenteling der
aarde" (tr. New proofs of the rotation of the earth). From 1878
to 1882 he was assistant to Johannes Bosscha, the director of
the TU Delft (then Delft Polytechnic), for whom he substituted
as lecturer in 1881 and 1882
He was married to Maria Adriana Wilhelmina Elisabeth Bijleveld
(m. 1887) and had one child, named Albert. His brother Menso
Kamerlingh Onnes (1860–1925) was a fairly well known painter
(and father of another painter, Harm Kamerlingh Onnes), while
his sister Jenny married another famous painter, Floris
Verster (1861–1927).
Ørsted ,Hans Christian
Hans Christian Ørsted, often
rendered Oersted in English; 14 August
1777 – 9 March 1851) was a
Danish physicist and chemist who
discovered that electric
currents create magnetic fields, an
important aspect ofelectromagnetism. He
shaped post-Kantian philosophy and
advances in science throughout the late
19th century.
In 1824, Ørsted founded Selskabet for
Naturlærens Udbredelse (SNU), a society to disseminate knowledge
of the natural sciences. He was also the founder of predecessor
organizations which eventually became
the Danish Meteorological
Institute and the Danish Patent and
Trademark Office. Ørsted was the first modern thinker to
explicitly describe and name the thought experiment.
A leader of the so-called Danish Golden Age, Ørsted was a close
friend of Hans Christian Andersen and the brother of politician
Danish physicist & chemist
20. 108
and jurist Anders Sandøe Ørsted, who eventually served as Danish
prime minister (1853–54). The oersted (Oe), the cgs unit
of magnetic H-field strength, is named after him.
Ørsted was born in Rudkøbing. As a young boy Ørsted developed
his interest in science while working for his father, who owned
a pharmacy. He and his brother Anders received most of their
early education through self-study at home, going to Copenhagen
in 1793 to take entrance exams for theUniversity of Copenhagen,
where both brothers excelled academically. By 1796 Ørsted had
been awarded honors for his papers in
both aesthetics and physics. He earned his doctorate in 1799 for
a dissertation based on the works of Kant entitled "The
Architectonics of Natural Metaphysics".
0smosis
Osmosis is the spontaneous
net movement
of solvent molecules through
a
partially permeable membrane
into a region of
higher solute concentration,
in the direction that tends
to equalize the solute
concentrations on the two
sides. It may also be used to
describe a physical process
in which any solvent moves,
without input of
energy, across a semipermeable membrane (permeable to
the solvent, but not the
solute) separating two
solutions of different concentrations. Although osmosis does not
require input of energy, it does use kinetic energy and can be
made to do work.
The osmotic pressure is defined to be the pressure required to
maintain an equilibrium, with no net movement of solvent.
Osmotic pressure is a colligative property, meaning that the
One frame of a computer simulation of osmosis
21. 109
osmotic pressure depends on the molar concentration of the
solute but not on its identity.Osmosis is an essential aspect
in biological systems, as biological membranes are
semipermeable.
In general, these membranes are impermeable to large
and polar molecules, such as ions, proteins,
and polysaccharides, while being permeable to non-polar
and/orhydrophobic molecules like lipids as well as to small
molecules like oxygen, carbon dioxide, nitrogen, nitric oxide,
etc. Permeability depends on solubility, charge, or chemistry,
as well as solute size.
Water molecules travel through the plasma membrane, tonoplast
membrane (vacuole) or protoplast by diffusing across the
phospholipid bilayer via aquaporins (small transmembrane
proteins similar to those in facilitated diffusion and in
creating ion channels). Osmosis provides the primary means by
which water is transported into and out of cells.
The turgor pressure of a cell is largely maintained by osmosis
across the cell membrane between the cell interior and its
relatively hypotonic environment.
22. 110
P
Paradigm shift
In 1962, Thomas
Kuhn wrote The
Structure of
Scientific
Revolution, and
fathered, defined and
popularized the
concept of "paradigm
shift" Kuhn argues
that scientific advancement is not evolutionary, but rather is a
"series of peaceful interludes punctuated by intellectually
violent revolutions",
and in those
revolutions "one
conceptual world view
is replaced by
another".
Kuhn used the duck-rabbit optical illusion to
demonstrate the way in which a paradigm shift could
cause one to see the same information in an entirely
different way.
23. Think of a Paradigm Shift as a change from one way of thinking
to another. It's a revolution, a transformation, a sort of
metamorphosis. It just does not happen, but rather it is driven
by agents of change.
111
For example, agriculture changed early primitive society. The
primitive Indians existed for centuries roaming the earth
constantly hunting and gathering for seasonal foods and water.
However, by 2000 B.C., Middle America was a landscape of very
small villages, each surrounded by patchy fields of corn and
other vegetables.
Agents of change helped create a paradigm-shift moving
scientific theory from the Plolemaic system (the earth at the
center of the universe) to the Copernican system (the sun at the
center of the universe), and moving from Newtonian physics to
Relativity and Quantum Physics. Both movements eventually
changed the world view. These transformations were gradual as
old beliefs were replaced by the new paradigms creating "a new
gestalt" (p. 112).
Likewise, the printing press, the making of books and the use of
vernacular language inevitable changed the culture of a people
and had a direct affect on the scientific revo ution. Johann
Gutenberg's invention in the 1440's of movable type was an agent
of change. With the invention of the printing press, books
became readily available, smaller and easier to handle and cheap
to purchase. Masses of people acquired direct access to the
scriputures. Attitudes began to change as people were relieved
from church domination.
Similarly, agents of change are driving a new paradigm shift
today. The signs are all around us. For example, the
introduction of the personal computer and the internet have
impacted both personal and business environments, and is a
catalyst for a Paradigm Shift. We are shifting from a
mechanistic, manufacturing, industrial society to an organic,
service based, information centered society, and increases in
technology will continue to impact globally. Change is
inevitable. It's the only true constant.
In conclusion, for millions of years we have been evolving and
will continue to do so. Change is difficult. Human Beings
resist change; however, the process has been set in motion long
ago and we will continue to co-create our own experience. Kuhn
states that "awareness is prerequisite to all acceptable changes
of theory" (p. 67). It all begins in the mind of the person.
What we perceive, whether normal or metanormal, conscious or
unconscious, are subject to the limitations and distortions
produced by our inherited and socially conditional nature.
However, we are not restricted by this for we can change. We are
24. moving at an accelerated rate of speed and our state of
consciousness is transforming and transcending. Many are
awakening as our conscious awareness expands.
112
Photovoltaics
Photovoltaics (PV) is a method
of generating electrical
power by converting solar
radiation into direct current
electricity using semiconductor
s that exhibit the photovoltaic
effect. Photovoltaic power
generation employs solar
panels composed of a number
of solar cells containing a
photovoltaic material.
Materials presently used for
photovoltaics
include monocrystalline
silicon,polycrystalline
silicon, amorphous
silicon, cadmium telluride, and copper indium gallium
selenide/sulfide. Due to the increased demand for renewable
energy sources, the manufacturing of solar cells
and photovoltaic arrays has advanced considerably in recent
years.
Solar photovoltaics is a sustainable energy source. By the end
of 2011, a total of 71.1 GW had been installed, sufficient to
generate 85 TWh/year. And by end of 2012, the 100 GW installed
capacity milestone was achieved. Solar photovoltaics is now,
after hydro and wind power, the third most important renewable
energy source in terms of globally installed capacity. More than
100 countries use solar PV. Installations may be ground-mounted
(and sometimes integrated with farming and grazing) or built
into the roof or walls of a building (either building-integrated
photovoltaics or simply rooftop.
Driven by advances in technology and increases in manufacturing
scale and sophistication, the cost of photovoltaics has declined
steadily since the first solar cells were manufactured, and the
levelized cost of electricity (LCOE) from PV is competitive with
conventional electricity sources in an expanding list of
geographic regions. Net metering and financial incentives, such
Solar cells produce electricity directly
from sunlight.
25. as preferential feed-in tariffs for solar-generated electricity,
have supported solar PV installations in many countries. With
current technology, photovoltaics recoup the energy needed to
113
manufacture them in 3 to 4 years. Anticipated technology would
reduce time needed to recoup the energy to 1 to 2 years.
Photovoltaics are best known as a method for generating electric
power by using solar cells to convert energy from the sun into a
flow of electrons. The photovoltaic effect refers to photons of
light exciting electrons into a higher state of energy, allowing
them to act as charge carriers for an electric current. The
photovoltaic effect was first observed by Alexandre-Edmond
Becquerel in 1839. The term photovoltaic denotes the unbiased
operating mode of a photodiode in which current through the
device is entirely due to the transduced light energy. Virtually
all photovoltaic devices are some type of photodiode.
Solar cells produce direct current electricity from sun light
which can be used to power equipment or to recharge a battery.
The first practical application of photovoltaics was to power
orbiting satellites and other spacecraft, but today the
majority of photovoltaic modules are used for grid connected
power generation. In this case an inverter is required to
convert the DC to AC.
There is a smaller market for off-grid power for remote
dwellings, boats,recreational vehicles, electric cars, roadside
emergency telephones, remote sensing, and cathodic protection of
pipelines.
Photovoltaic power generation employs solar panels composed of a
number of solar cells containing a photovoltaic material.
Materials presently used for photovoltaics include
monocrystalline silicon,polycrystalline silicon, amorphous
silicon, cadmium telluride, and copper indium gallium
selenide/sulfide. Copper solar cables connect modules (module
cable), arrays (array cable), and sub-fields. Because of the
growing demand for renewable energy sources, the manufacturing
of solar cells and photovoltaic arrays has advanced considerably
in recent years.
Cells require protection from the environment and are usually
packaged tightly behind a glass sheet. When more power is
required than a single cell can deliver, cells are electrically
connected together to form photovoltaic modules, or solar
panels. A single module is enough to power an emergency
telephone, but for a house or a power plant the modules must be
arranged in multiples as arrays.
Photovoltaic power capacity is measured as maximum power output
under standardized test conditions (STC) in "Wp" (Watts peak).
26. The actual power output at a particular point in time may be
less than or greater than this standardized, or "rated," value,
114
depending on geographical location, time of day, weather
conditions, and other factors. Solar photovoltaic array capacity
factors are typically under 25%, which is lower than many other
industrial sources of electricity.
Pheromones
A pheromone (from Greek φέρω phero
"to bear" and hormone, from Greek
ὁρμή "impetus") is a secreted or
excreted chemical factor that
triggers a social response in
members of the same species.
Pheromones are chemicals capable of
acting outside the body of the
secreting individual to impact the
behavior of the receiving
individual. There are alarm
pheromones, food trail
pheromones, sex pheromones, and
many others that affect behavior or
physiology. Pheromones are used from basic
unicellular prokaryotes to complex multicellular eukaryotes.
Their use among insects has been particularly well documented.
In addition, some vertebrates and plants communicate by using
pheromones.
The term "pheromone" was introduced by Peter Karlson and Martin
Lüscher in 1959, based on the Greek word pherein (to transport)
and hormone (to stimulate). They are also sometimes classified
as ecto-hormones. They were researched earlier by various
scientists, including Jean-Henri Fabre, Joseph A. Lintner,
Adolph Butenandt, and ethologist Karl von Frisch who called
them various names like "alarm substances." These chemical
messengers are transported outside of the body and effect neuro
circuits, including the autonomous nervous system with hormone
or cytokine mediated physiological changes, inflammatory
Fanning honeybee exposes Nasonovgland
(white-at tip of abdomen) releasing
pheromone to entice swarm into an
empty hive
27. signaling,immune system changes and/or behavioral change in the
recipient. They proposed the term to describe chemical signals
115
from conspecifics that elicit innate behaviors soon after the
German Biochemist Adolf Butenandt had characterized the first
such chemical, bombykol, a chemically well-characterized
pheromone released by the female silkworm to attract mates.
There are physical limits on the practical size of organisms
employing pheromones, because at small sizes pheromone diffuses
away from the source organism faster than it can be produced,
and a sensible concentration accumulates too slowly to be
useful. For this reason, bacteria are too small to use
pheromones as sex attractants on an individual basis. However,
they do use them to determine the local population density of
similar organisms and control behaviors that take more time to
execute (e.g. pheromones are used in quorum sensing or to
promote natural competence for transformation, i.e. sexual gene
transfer). In similar manner, the simple animals rotifers are,
it appears, also too small for females to lay down a useful
trail, but in the slightly larger copepods the female leaves a
trail that the male can follow.
Polymer
A polymer /ˈpɒlɨmər/is a large molecule, or macromolecule,
composed of many repeated subunits, known as monomers. Because
of their broad range of properties, both synthetic and natural
polymers play an essential and ubiquitous role in everyday
life. Polymers range from familiar synthetic plastics such as
polystyrene (or styrofoam) to natural biopolymers such
as DNAand proteins that are fundamental to biological structure
and function. Polymers, both natural and synthetic, are created
via polymerization of many monomers. Their consequently
largemolecular mass relative to small molecule compounds
produces unique physical properties, including toughness,
viscoelasticity, and a tendency to form glasses and
semicrystalline structures rather than crystals.
The term "polymer" derives from the ancient Greek word
πολύς (polus, meaning "many, much") and μέρος (meros,
28. meaning "parts"), and refers to a molecule whose structure is
composed of multiple repeating units, from which originates
116
a characteristic of high relative molecular mass and attendant
properties. The units composing polymers derive, actually or
conceptually, from molecules of low relative molecular mass. The
term was coined in 1833 by Jöns Jacob Berzelius, though with a
definition distinct from the modern IUPAC definition.[8][9] The
modern concept of polymers as covalently bonded macromolecular
structures was proposed in 1920 by Hermann Staudinger, who spent
the next decade finding experimental evidence for this
hypothesis.
Polymers are studied in the fields of biophysics and
macromolecular science, and polymer science(which includes
polymer chemistry and polymer physics). Historically, products
arising from the linkage of repeating units by covalent chemical
bonds have been the primary focus of polymer science; emerging
important areas of the science now focus on non-covalent
links. Polyisoprene of
latex rubber and the
polystyrene of styrofoam are
examples of polymeric
natural/biological and
synthetic polymers,
respectively. In biological
contexts, essentially all
biological macromolecules
i.e.,proteins (polyamides)
, nucleic
acids (polynucleotides),
and polysaccharides—are
purely polymeric, or are composed in large part of polymeric
components—e.g., isoprenylated/lipid-modified glycoproteins,
where small lipidic molecule and oligosaccharide modifications
occur on the polyamide backbone of the protein.
Projectile motion
Appearance of real linear polymer chains as
recorded using an atomic force microscope on
a surface, under liquid medium. Chaincontour
length for this polymer is ~204 nm; thickness
is ~0.4 nm.
29. Projectile is defined as, any body thrown with some initial
velocity, which is then allowed to move under the action of
117
gravity alone, without
being propelled by any
engine or fuel. The path
followed by a projectile is
called its trajectory. A
projectile moves at a
constant speed in the
horizontal direction while
experiencing a constant
acceleration of 9.8
m/s2
downwards in the
vertical direction. To be
consistent, we define the
up or upwards direction to
be the positive direction.
Therefore the acceleration
of gravity is, -9.8 m/s2
.
The speed in the horizontal direction is 'vx' and this speed
doesn't change. The equation which predicts the position at any
time in the horizontal direction is simply,
Because gravity has a downward pull, the vertical velocity
changes constantly. The equation that predicts the vertical
velocity at any time 'vy' is
The 'Voy' is simply the original velocity in the vertical or y-
direction. To calculate the position in the y-direction, the
full distance formula must be used. 'Yo', represents the original
position in the y-direction.
Acceleration for projectiles near the Earth's surface is -9.8
m/s2
. We don't re-write the equation with a negative sign.
Rather, we use the negative acceleration value when solving
problems.
When a projectile is launched horizontally a ball rolls off a
table, a car runs off the edge of a cliff, etc. Here the
original y-velocity is zero. For example, if the projectile
Parabolic Water Tragectory
30. drops 10 meters, you can set the Yo = 0 and Yf = -10 m. Or, you
can set Yo = 10 m and Yf = 0. Either works out the same.
118
Q
Quantum
Quantum physics is a
branch of science
that deals with
discrete, indivisible
units of energy
called quanta as
described by the
Quantum Theory. There
are five main ideas
represented in
Quantum Theory:
1. Energy is not continuous, but comes in small but discrete
units.
31. 2. The elementary particles behave both like
particles and like waves.
3. The movement of these particles is inherently random.
4. It is physically impossible to know both the position and
the momentum of a particle at the same time. The more
precisely one is known, the less precise the measurement of
the other is
119
5. The atomic world is nothing like the world we live in.
While at a glance this may seem like just another strange
theory, it contains many clues as to the fundamental nature of
the universe and is more important then even relativity in the
grand scheme of things (if any one thing at that level could be
said to be more important then anything else). Furthermore, it
describes the nature of the universe as being much different
then the world we see. As Niels Bohr said, "Anyone who is not
shocked by quantum theory has not understood it."
Quartz
Quartz is the second
most
abundant mineral in
the Earth's continental
crust, after feldspar.
It is made up of a
continuous framework of
SiO4 silicon–
oxygen tetrahedra, with
each oxygen being shared between two tetrahedra, giving an
overall formula SiO2.
There are many different varieties of quartz, several of which
are semi-precious gemstones.
32. Especially in Europe and the Middle East, varieties of quartz
120
have been since antiquity the most commonly used minerals in the
making of jewelry and hardstone carvings.
The word "quartz" is derived from the German word "Quarz" and
its Middle High German ancestor "twarc", which probably
originated in Slavic (cf. Czech tvrdý ("hard"),
Polish twardy ("hard").
Quartz belongs to the trigonal crystal system. The ideal crystal
shape is a six-sided prism terminating with six-
sided pyramids at each end. In nature quartz crystals are often
twinned, distorted, or so intergrown with adjacent crystals of
quartz or other minerals as to only show part of this shape, or
to lack obvious crystal faces altogether and appear massive.
Well-formed crystals typically form in a 'bed' that has
unconstrained growth into a void; usually the crystals are
attached at the other end to a matrix and only one termination
pyramid is present. However doubly-terminated crystals do occur
where they develop freely without attachment, for instance
within gypsum. A quartz geode is such a situation where the void
is approximately spherical in shape, lined with a bed of
crystals pointing inward. α-quartz crystallizes in the trigonal
crystal system, space group P3121 and P3221 respectively. β-
quartz belongs to the hexagonal system, space group P6222
and P6422, respectively. These space groups are truly chiral
(they each belong to the 11 enantiomorphism pairs). Both α-
quartz and β-quartz are examples of chiral crystal structures
composed of achiral building blocks (SiO4 tetrahedra in the
present case). The transformation between α- and β-quartz only
involves a comparatively minor rotation of the tetrahedra with
respect to one another, without change in the way they are
linked.
Quartzite
33. Quartzite (from German Quar
zit) is a hard, non-
foliated metamorphic
rock which was originally
pure quartzsandstone.
Sandstone is converted into
quartzite through heating
and pressure usually
related to tectonic
compression within orogenic
belts. Pure quartzite is
usually
121
white to grey, though
quartzites often occur in
various shades of pink and
red due to varying amounts
of iron oxide (Fe2O3).
Other colors, such as yellow, green, blue and orange, are due to
other mineral impurities.
When sandstone is cemented to quartzite, the
individual quartz grains recrystallize along with the former
cementing material to form an interlocking mosaic of quartz
crystals. Most or all of the original texture and sedimentary
structures of the sandstone are erased by the metamorphism. The
grainy, sandpaper-like surface becomes glassy in appearance.
Minor amounts of former cementing materials, iron oxide, silica,
carbonate and clay, often migrate during recrystallization and
metamorphosis. This causes streaks and lenses to form within the
quartzite.
Orthoquartzite is a very pure quartz sandstone composed of
usually well rounded quartz grains cemented bysilica.
Orthoquartzite is often 99% SiO2 with only very minor amounts of
iron oxide and trace resistant minerals such
as zircon, rutile and magnetite. Although few fossils are
normally present, the original texture and
sedimentary structures are preserved.
The term is also traditionally used for quartz-cemented quartz
arenites, and both usages are found in the literature. The
typical distinction between the two (since each is a gradation
into the other) is a metamorphic quartzite is so highly
cemented, diagenetically altered, and metamorphosized so that it
will fracture and break across grain boundaries, not around
them. Quartzite is very resistant to chemical weathering and
often forms ridges and resistant hilltops. The nearly pure
34. silica content of the rock provides little for soil, therefore,
the quartzite ridges are often bare or covered only with a very
thin layer of soil and (if any) little vegetation.
122
Because of its hardness and angular shape, crushed quartzite is
often used as ballast. Quartzite is a decorative stone and may
be used to cover walls, as roofing tiles, as flooring, and stair
steps. Crushed quartzite is sometimes used in road construction.
High purity quartzite is used to produce ferrosilicon,
industrial silica sand, silicon and silicon carbide. During
the Stone Age quartzite was used, in addition to flint, quartz,
and other lithic raw materials, for making stone tools.
Quasars and
QSOs
These objects were
named Quasistellar
Radio
Sources (meaning
"star-like radio
sources") which
was soon
contracted
to quasars. Later,
it was found that
many similar objects did not emit radio waves. These were
termed Quasistellar Objects or QSOs. Now, all of these are often
termed quasars (Only about 1% of the quasars discovered to date
have detectable radio emission).
Here are some Hubble Space Telescope quasar images, and the
following figure shows the quasar 3C273, which was the first
quasar discovered and is also the quasar with the greatest
apparent brightness. It will be discussed further below.
The quasars were deemed to be strange new phenomena, and
initially there was considerable speculation that new laws of
physics might have to be invented to account for the amount of
energy that they produced.
Quasars
35. 123
The quasar 3C273. Left image shows the quasar and the jet. Right image
superposes on this contours of radio frequency intensity. The sharp radial
lines from the quasar are optical spike artifacts because of its brightness
However, subsequent research has shown that the quasars are
closely related to the active galaxies that have been studied at
closer distances. We now believe quasars and active galaxies to
be related phenomena, and that their energy output can be
explained using the theory of general relativity. In that sense,
the quasars are certainly strange, but perhaps are not
completely new phenomena.
The quasars are thought to be powered by supermassive rotating
black holes at their centers. Because they are the most luminous
objects known in the universe, they are the objects that have
been observed at the greatest distances from us. The most
distant are so far away that the light we see coming from them
was produced when the Universe was only one tenth of its present
age.
The present belief is that quasars are actually closely related
to active galaxies such as Seyfert Galaxies or BL Lac objects in
that they are very active galaxies with bright nuclei powered by
enormous rotating black holes. However, because the quasars are
at such large distances, it is difficult to see anything other
than the bright nucleus of the active galaxy in their case.
36. 124
Quine, Willard Van Orman
W. V. O. Quine (1908-2000) did
not conceive of philosophy as an
activity separate from the
general province of empirical
science. His interest in science
is not best described as a
philosophy of science but as a
set of reflections on the nature
of science that is pursued with
the same empirical spirit that
animates scientific inquiry.
Quine’s philosophy should then
be seen as a systematic attempt
to understand science from
within the resources of science
itself. This project
investigates both the
epistemological and ontological
dimensions of scientific
theorizing. Quine’s epistemological concern is to examine our
successful acquisition of scientific theories, while his
ontological interests focus on the further logical regimentation
of that theory. He thus advocates what is more famously known as
‘naturalized epistemology’, which consists of his attempt to
provide an improved scientific explanation of how we have
developed elaborate scientific theories on the basis of meager
sensory input. Quine further argues that the most general
features of reality can be examined through the use of formal
logic by clarifying what objects we must acknowledge as real
given our acceptance of an overarching systematic view of the
world. In pursuing these issues, Quine reformulates and thus
transforms these philosophical concerns according to those
standards of clarity, empirical adequacy, and utility that he
takes as central to the explanatory power of empirical science.
While few philosophers have adopted Quine’s strict standards or
accepted the details of his respective positions, the general
empirical reconfiguration of philosophy and philosophy of
science recommended by his naturalism has been very influential.
Willard Van Orman Quine
38. 126
Reproduction (or procreation) is the biological process by which
new "offspring" individual organisms are produced from their
"parents". Reproduction is a fundamental feature of all known
life; each individual organism exists as the result of
reproduction. The known methods of reproduction are broadly
grouped into two main types: sexual and asexual.
In asexual reproduction, an individual can reproduce without
involvement with another individual of that species. The
division of a bacterial cell into two daughter cells is an
example of asexual reproduction. Asexual reproduction is not,
however, limited to single-celled organisms. Most plants have
the ability to reproduce asexually and the ant
species Mycocepurus smithii is thought to reproduce entirely by
asexual means.
Sexual reproduction typically requires the involvement of two
individuals or gametes, one each from opposite type of sex. The
propagation of organisms can also occur through cloning.
Asexual reproduction
39. Asexual reproduction is the process by which an organism creates
a genetically similar or identical copy of itself without a
contribution of genetic material from another
individual. Bacteria divide asexually via binary
fission; viruses take control of host cells to produce more
viruses; Hydras (invertebrates of the order Hydro idea)
and yeasts are able to reproduce by budding. These organisms
often do not possess different sexes, and they are capable of
"splitting" themselves into two or more individuals. On the
other hand, some of these species that are capable of
reproducing asexually, like hydra, yeast (Mating of yeasts)
and jellyfish, may also reproduce sexually. For instance, most
plants are capable of vegetative reproduction—reproduction
without seeds or spores—but can also reproduce sexually.
Likewise, bacteria may exchange genetic information
by conjugation. Other ways of asexual reproduction
include parthenogenesis, fragmentation and spore formation that
involves only mitosis. Parthenogenesis (from the Greek παρθένος
parthenos, "virgin", + γένεσις genesis, "creation") is the
growth and development of
embryo or seed without fertilization by a male. Parthenogenesis
occurs naturally in some species, including lower plants (where
it is called apomixis), invertebrates (e.g. water fleas, aphids,
some bees and parasitic wasps).
127
Sexual reproduction
Sexual reproduction is a biological process by which organisms
create descendants that have a combination of genetic material
contributed from two (usually) different members of the species.
(Self-fertilization requires only one organism.) Each of two
parent organisms contributes half of the offspring's genetic
makeup by creating haploid gametes. Most organisms form two
different types of gametes. In these anisogamous species, the
two sexes are referred to as male (producing sperm or
microspores) and female (producing ova or megaspores).
In isogamous species, the gametes are similar or identical in
form (isogametes), but may have separable properties and then
may be given other different names (isogamy). For example, in
the green alga, Chlamydomonas reinhardtii, there are so-called
"plus" and "minus" gametes. A few types of organisms, such
as ciliates, Paramecium aurelia, have more than two types of
"sex", called syngens.
40. Reptile
Phylogentic classifications group mammal-like reptiles, like this Varanodon, with
other synapsids, not with extant reptiles.
128
Reptiles, the class Reptilia, are an evolutionary grade of
animals, comprising today's turtles, crocodilians, snakes,
lizards, and tuatara, as well as many extinct groups. A reptile
is any amniote (a tetrapod whose egg has an additional membrane,
originally to allow them to lay eggs on land) that is neither
a mammal nor a bird. Unlike mammals, birds, and certain extinct
reptiles, living reptiles have scales orscutes (rather than fur
or feathers) and are cold-blooded. Advocates of phylogenetic
nomenclature regard the traditional category 'Reptilia' to be
invalid, as not all descendants of a common ancestor are
included. However, in practice, these non-
cladistic classifications, such as reptile, fish, and amphibian,
remain in use by some biologists, especially in popular books
written for a general audience. The historically combined study
of reptiles and amphibians is called herpetology.
The earliest known reptiles originated around 340-335 million
years ago during the Carboniferous period, having evolved from
advancedreptile-like amphibians that became increasingly adapted
to life on dry land. Some early examples include the lizard-
like Hylonomus,Casineria and possibly Westlothiana, although the
latter may be an advanced land-dwelling amphibian. In addition
41. to the living reptiles, there are many diverse groups that are
now extinct, in some cases due to mass extinction events. In
particular, the K–Pg extinctionwiped out
the pterosaurs, plesiosaurs, ornithischians, and sauropods, as
well as many species
of theropods (e.g. tyrannosaurs anddromaeosaurids), crocodylifor
ms, and squamates (e.g. mosasaurids).
Modern reptiles inhabit every continent with the exception of
Antarctica. Several living subgroups are recognized:
Testudines (turtles, terrapins and tortoises): approximately
400 species
Sphenodontia (tuatara from New Zealand): 2 species
Squamata (lizards, snakes, and worm lizards): over 9,600
species
Crocodilia (crocodiles, gavials, caimans, and alligators): 25
species
Although they have scutes on their feet and lay eggs, birds have
historically been excluded from the reptiles. They, therefore,
do not appear on the list above. However, as some reptiles are
more closely related to birds than they are to other reptiles —
129
crocodiles are more closely related to birds than they are to
lizards — cladistic writers who prefer a more
unified (monophyletic) grouping usually also include the birds,
which include over 10,000 species.
Rhenium
42. Rhenium is a chemical element with the symbol Re and atomic
number 75. It is a silvery-white, heavy, third-row transition
metal in group 7 of the periodic table. With an estimated
average concentration of 1 part per billion (ppb), rhenium is
one of the rarest elements in the Earth's crust. Discovered in
1925, rhenium was the last stable element to be discovered. It
was named after the river Rhine in Europe.
Nickel-based super alloys of rhenium are used in the
combustion chambers, turbine blades, and exhaust nozzles of jet
engines. These alloys contain up to 6% rhenium, making jet
engine construction the largest single use for the element, with
the chemical industry's catalytic uses being next-most
important.
Rhenium (Latin: Rhenus meaning: "Rhine") was the last element to
be discovered having a stable isotope (other new radioactive
elements have
been discovered
in nature since
then, such
as neptunium and plutonium). The existence of a yet undiscovered
130
element at this position in the periodic had been first
predicted by Dmitry Mendeleev. Other calculated information was
obtained by Henry Moseley in 1914. It is generally considered to
have been discovered by Walter Noddack, Ida Tacke, and Otto
Berg in Germany. In 1925 they reported that they detected the
element in platinum ore and in the mineral columbite. They also
found rhenium in gadolinite and molybdenite. In 1928 they were
able to extract 1 g of the element by processing 660 kg of
43. molybdenite. It was estimated in 1968 that 75% of the rhenium
metal in the United States was used for research and the
111
development of refractory metal alloys. It took several years
from that point on before the super alloys became widely used.
Rheumatoid arthritis
Rheumatoid arthritis (RA) is an autoimmune disease that results
in a chronic, systemic inflammatory disorder that may affect
many tissues and organs, but principally attacks flexible
(synovial) joints. The process involves an inflammatory response
of the capsule around the joints (synovium) secondary to
swelling (turgescence) of synovial cells, excess synovial fluid,
and the development of fibrous tissue (pannus) in the synovium.
The pathology of the disease process often leads to the
destruction of articular cartilage and ankylosis (fusion) of the
joints. RA can also
produce diffuse
inflammation in
the lungs, the membrane
around the heart
131
(pericardium), the
membranes of the lung
(pleura), and white of
the eye (sclera), and
also nodular lesions,
mostcommonin subcutaneous tissue. Although the cause of RA is
unknown, autoimmunity plays a big part, and RA is a systemic
autoimmune disease. It is a clinical diagnosis made on the basis
of symptoms, physical exam, radiographs (X-rays) and labs.
Hand affected by rheumatoid arthritis
44. Rheumatic fever
Rheumatic fever is an inflammatory disease that occurs following
a Streptococcus pyogenes infection, such as streptococcal
pharyngitis. Believed to be caused by antibody cross-reactivity
that can involve the heart, joints, skin, and brain, the illness
typically develops two to three weeks after a streptococcal
infection. Acute rheumatic fever commonly appears in children
between the ages of 6 and 15, with only 20% of first-time
attacks occurring in adults. The illness is so named because of
its similarity in presentation to rheumatism.
132
Skin with rheumatic fever.
45. S
Saturated fat
Saturated fat is fat that consists of triglycerides containing
only saturated fatty acids. Saturated fatty acids have no double
bonds between the
individual carbon
atoms of the fatty acid
chain. That is, the chain
of carbon atoms is fully
"saturated"
with hydrogen atoms.
There are many kinds of
naturally occurring
saturated fatty acids,
which differ mainly in
number of carbon atoms,
from 3 carbons (propionic
acid) to 36 (hexatriacontanoic acid).
Various fats contain different proportions of saturated
and unsaturated fat. Examples of foods containing a high
proportion of saturated fat include animal fats such
as cream, cheese, butter, and ghee; suet, tallow, lard, and
fatty meats; as well as certain vegetable products such
as coconut oil, cottonseed oil, palm kernel oil, chocolate, and
many prepared foods.
Schleiden, Matthias Jakob
46. Schleiden, Matthias Jakob (5 April 1804 – 23 June 1881) was
a German botanist and co-founder of the cell theory, along
133
with Theodor Schwann and Rudolf
Virchow.
Born in Hamburg, Schleiden was
educated at Heidelberg, then
practiced law in Hamburg, but soon
developed his love for
the botany into a full-time
pursuit. Schleiden preferred to
study plant structure under
the microscope. While a professor
of botany at the University of
Jena, he wrote Contributions to
Phytogenesis (1838), in which he
stated that the different parts of
the plant organism are composed of
cells. Thus, Schleiden and Schwann became the first to formulate
what was then an informal belief as a principle of biology equal
in importance to the atomic theory of chemistry. He also
recognized the importance of the cell nucleus, discovered in
1831 by the Scottish botanist Robert Brown, and sensed its
connection with cell division.
Schleiden was one of the first German biologists to
accept Charles Darwin's theory of evolution. He became professor
of botany at the University of Dorpat in 1863. He concluded that
all plant parts are made of cells and that an embryonic plant
organism arises from the one cell. He died in Frankfurt am
Main on 23 June 1881.
Sputnik 1
Sputnik 1 was the
first artificial Earth
satellite. It was a
58 cm (23 in) diameter
polished metal sphere,
with four external radio
antennas to broadcast
radio pulses. The Soviet
Matthias Jakob Schleiden
First man-made satellite to orbit the earth.
47. Union launched it into an elliptical low Earth
134
orbit on 4 October 1957. It was visible all around the Earth and
its radio pulses were detectable. The surprise success
precipitated the American Sputnik crisis, began the Space
Age and triggered the Space Race, a part of the larger Cold War.
The launch ushered in new political, military, technological,
and scientific developments.
Sputnik itself provided scientists with valuable information.
The density of the upper atmosphere could be deduced from
its drag on the orbit, and the propagation of its radio signals
gave information about the ionosphere.
Sputnik 1 was launched during the International Geophysical
Year from Site No.1/5, at
the 5th Tyuratam range,
in Kazakh SSR (now at the
Baikonur Cosmodrome). The satellite travelled at about 29,000
kilometers per hour (18,000 mph), taking 96.2 minutes to
complete each orbit. It transmitted on 20.005 and 40.002 MHz
which were monitored by amateur radio operators throughout the
world. The signals continued for 22 days until the transmitter
batteries ran out on 26 October 1957. Sputnik 1 burned up on 4
January 1958, as it fell from orbit upon reentering Earth's
atmosphere, after travelling about 70 million km (43.5 million
miles) and spending 3 months in orbit.
Steroid
A steroid is a
type of organic
compound that
contains a
characteristic
arrangement of
Figure 1 Sputnik 1 was the first man-made object
to orbit the Earth.
48. four cycloalkane rings that are joined to each other. Examples
of steroids include the dietary lipid cholesterol, the sex
135
hormones estradiol and testosterone and the anti-
inflammatory drug dexamethasone.
The core of steroids is composed of seventeen carbon atoms
bonded together that take the form of four fused rings:
three cyclohexane rings (designated as rings A, B and C in the
figure to the right) and one cyclopentane ring (the D ring). The
steroids vary by the functional groups attached to this four-
ring core and by the oxidation state of the rings. Sterols are
special forms of steroids, with a hydroxyl group at position-3
and a skeleton derived from cholestane.
Hundreds of distinct steroids are found
in plants, animals and fungi. All steroids are made in cells
either from the sterols lanosterol (animals and fungi, see below
right) or from cycloartenol (plants). Both lanosterol and
cycloartenol are derived from the cyclization of
the triterpene squalene.
Storm surge
Storm surge is an
offshore rise of
water associated
with a low
pressure weather
system,
typically tropical
cyclones and
strong extra
tropical cyclones.
Storm surges are
caused primarily by
high winds pushing
on the ocean's
49. surface. The wind causes the water to
136
pile up higher than the ordinary sea level. Low pressure at the
center of a weather system also has a small secondary effect, as
can the bathymetry of the body of water. It is this combined
effect of low pressure and persistent wind over a shallow water
body which is the most common cause of storm surge flooding
problems. The term "storm surge" in casual (non-scientific) use
is storm tide; that is, it refers to the rise of water
associated with the storm, plus tide, wave run-up, and
freshwater flooding. "Tidal surge" is incorrect since there is
no such thing. When referring to storm surge height, it is
important to clarify the usage, as well as the reference point.
The U.S. National Hurricane Center defines storm surge as water
height above predicted astronomical tide level, and storm tide
as water height above NGVD-29, a 1929 benchmark of mean sea
level. Most casualties during a tropical cyclone occur during
the storm surge.
50. 137
INDEX
M
Maltose, pp.77-78
Mantle, pp.78-79
Momentum, pp.80-81
Mudslide, pp.81-82
Myelin, pp.82-83
N
Neon, pp.84-85
Neodymium , p. 87
Neptunium, p.86
Newton, Isaac,
pp.85-86
Niobium ,p.88
O
Ocean, pp.89-90
Ohm’s law, pp.90-
91
Onnes, Heike
Kamerlingh, p.91
Orsted, Hans
Christian , p.92
Osmosis, p.93
P
Paradigm Shift,
pp.94-95
Pheromones, pp.97-
98
Photovoltaics,
pp.95-97
Polymer, pp. 98-
100
Projectile Motion,
pp. 101-101
Q
Quantum, p.102
Quartz, pp.102-103
Quartzite, pp.104-
105
Quasars and quo’s,
pp.105-107
Quine, Willard Van
Orman, p. 107
R
Reproduction ,
pp.108-109
Reptiles, pp.109-
111
Rhenium , pp.111-
112
Rheumatoid
arthritis, p.112
Rheumatic fever,
p.112
S
Saturated fat,
p.113
Schleiden,
Matthias Jakob,
pp.113-114
51. Sputnik 1, pp.114-
115
Steroid, pp.115-
116
Storm surge, p.
116
Table of Contents
I. Title Page
II. Acknowledgement
III. Maltose
Mantle
Momentum
Mudslide
Myelin
IV. Neon
Neodymium
Neptunium
Newton, Isaac
Niobium
V. Ocean
Ohm’s law
Onnes, Heike Kamerlingh
Orsted, Hans Christian
Osmosis
VI. Paradigm Shift
Pheromones