CERAMICS:

1. Ceramics include a vast variety of inorganic, non metallic materials which require high temperature heating for preparation.
2. the most famous forms of ceramic are pottery; bricks, tiles and sanitary ware.
3. In fact the ceramics have a wide variety of usage in most sectors especially in the industrial sector.

RAW MATERIAL:
1. The raw material available for ceramic preparation is usually the clay which is found beneath the top soil.
2. This material is formed through the break down process of rocks affected from the chemical processes and the weather conditions.
3. This raw material is very cheap and can be found in huge quantity.
This raw material when mixed with water can be shaped and molded in any form according to the requirements or usage. It becomes hard at heating thus making it more durable and strong.
4.
KINDS: Three kinds of pottery are in use at the present times.
1. EARTHENWARE
2. STONEWARE
3. PORCELAIN

EARTHENWARE:
One of the cheapest and common style of pottery is earthenware. It is easy to prepare and is heated at low temperature. However it is not durable and is dull, porous and absorbent.
STONEWARE:
This kind of pottery is extremely hard and strong as is employed in the making of heavy dishes or jugs, sanitary wares etc. However it can hold liquids and is semi- vitreous and glass like, unlike earthenware.
PORCELAIN:
This is the finest and the most refined form of pottery. It is translucent and strong light can shine through it. Porcelain is also called chinaware as the original technique originated from China.











Plastic
1. Celluloid
2. Bakelite

Classification of Plastic
1. House hold plastic
2. Industrial plastics

House hold plastic
1. Soft plastic
2. Hard plastic
3. Transparent plastic
4. Resistance
5. Decorative

Industrial
1. Thermosetting
2. Thermo plastic

Plastic
1. Plastics are synthetic polymeric substance having to change shapes up on heating
2. Basically plastic is Greek word” Plastikos “(able to be molded)
3. In 1868, first plastic (celluloid) used in table tense ball and guitar picks was introduce.

4. Chemical composition
5. Cellulose nitrate + camphor= celluloid

6. In 1909 Bakelite (2nd plastic) by Hedrick backland

Thermo setting

1. plastics are those which can not be melted and re melted , they can be melted onces , after melting
2. They become hard and acquire permanent shape
Example

1. Bakelite
2. Polyester
3. Epoxy plastic
Its chemical composition changes on heating

Thermoplastic

Thermoplastic can melted and re melted against and again like candle
Example
1. Nylon
2. Polyethylene

Importance for industrial
1. Electrical insulator (bad conductor of electricity)
2. Chemically resistance
3. Light weight as compare to metal
4. Anti allergic and hygienic
5. Resistant to fungi
6. Color, transparent ,color less
Limitation
Thy are non resistant to heat and sunlight



Laser

1. laser is abbreviation of light implication by stimulated emission of radiation

2. The laser is an intense beam of light in which all the waves have same wave length such light is known as chromatic

3. The laser beam travel in one direction where as ordinary light spread out that’s why ordinary light large distant area while laser does not spread

4. Due to this characteristics of the laser different figure can be displayed in space because laser is an amplified light

5. To raise the intensity of light it is amplified again and again , for this purpose two plane mirror are used

6. Usually crystal example ruby glass or semiconductor are used to make the laser beside these , some gases are also used for this purpose

Uses of the laser

1. Laser are used in telecommunication
2. A single laser beam can carry thousand of radio, TV, and telephone messages simultaneously

3. Laser are used in surveying and ranging

4. They are also used I surgeries of eyes, spinal cord and vascular surgery to delicate operation

5. Dentist used a laser to remove decay from tooth

6. Laser are used to initiate thermo nuclear relations
7. Laser are used in holography , in which three dimensional images are produced
8. Laser played a major role in anti-satellite and ballistic missiles weapons

Types of laser

There are four types of the laser

1. Solid state laser
2. Semi conductor laser
3. Gas laser
4. Liquid laser





Radar

1. Radar stands for radio, angle, direction and range.
2. It was designed to detect and find the range of moving object.
3. It was invented by AH Taylor Leo c young

Principle of working

1. Radar consists of generator of electro magnetic radiation of centimeter wave length.

2. The pulses of electromagnetic radiation are transmitted in the form of the beam from a highly direction aerial

3. The objects are movable or fixed which lie in the way of this radiation; reflect them back to transmitter which also acts as receiver.

4. The direction of the object can be certain by the direction of aerial and time interval b/w transmitted beam and its echo

5. As measured with help of cathode ray tube indictor gave measure of distant of that object

Main uses of the radar

1. Radar is mainly used for defense systems by which the direction of the incoming air craft from hostile country is defected





















Balanced Diet:


• “The food which contains all essential food nutrients which are necessary and essential for healthy growth of the body and proper functioning of the whole parts of body.”

• Food is a complex mixture of chemical substances.

• It performs following useful functions when eaten and absorbed by the body.
i) Produces energy
ii) Promote growth
iii) Repair the tissues
iv) Regulate various processes

• Nutrients are the chemical components of food capable of performing above functions.
• Example: milk is a balanced diet although it does not contain iron.

Following are the major components of Balanced Diet and their source and functions:

i) Carbohydrates
• Source: Honey, Sugarcane, Wheat, Maize, Potatoes.
• Functions: Provide energy
ii) Fats:
• Source: Butter, Cheese, Soya bean, Mustard etc.
• Functions: Provide Energy

iii) Proteins:
• Source: Meat, Eggs, Fish, Milk, Pulses etc.
• Functions: Essential for growth

iv) Vitamins:
• Source: Fruits and Vegetables.
• Functions: Important for proper physiologic and metabolic functions of the body.
• Types:
a) Water Soluble Vitamins: B1, B2, B6, B12, C
b) Fat Soluble vitamins: A, D, E, K

v) Minerals: Minerals are those inorganic substances which play a key role in the maintenance and building of the body tissues. The most important minerals of balanced diet are as under:
• Phosphorus: is necessary for bones and teeth.
• Iron: is an essential component of blood.
• Iodine: is necessary for thyroxin which is secreted from thyroid gland.
• Calcium: is necessary for bone development.

vi) Water:
• Source: Fruits, Vegetables
• Functions: It is constituent of blood, lymph, hormones and other secretions of the
Lunar Eclipse:

• The partial or complete obscuration of light of moon For an observer on the earth is called lunar eclipse.
• It takes place when the earth comes in position between the sun and the moon.
• In this way, the shadow of the earth is cast on the moon and the moon does not get sunlight in this position. Lunar eclipse occurs only when there is full moon.
• But this does not happen on every full moon because of inclination of the axis of earth to its orbit.

Solar Eclipse:

• Solar eclipse occurs when the moon comes in between the Sun and the earth and its shadow is cast across the face of the earth.
• The solar eclipse occurs when the moon moves to a position between the Sun and the Earth.
• During this process it throws shadow on the earth.
• This shadow is categorized in umbra and penumbra.
• The people who are in the umbra region are unable to see the sun at all.
• This condition is known as the total eclipse of the sun.
• While the people in penumbra region can see the sun partly this is known as the partial eclipse of the sun.
• This happens with the new moon when the moon is in conjunction with the sun.
• This does not happen at every new moon because of the inclination of the orbit of the moon to the orbit of earth around the sun.
Asteroids:
• Asteroids are also known as planetoids.
• These are small, irregularly shaped rocky objects which orbit the Sun between the orbits of Mars and Jupiter.
• Asteroids are also known as the minor planets.
Basically the word Asteroid means “Starlike”.
• Ceres asteroid was the first to be discovered.





Meteorites:
Meteorites are small chunks of iron and rock thought to be resulted from collisions between asteroids. They also may be formed when comets disintegrate into fragments. Meteorites enter the earth’s atmosphere and become a meteor. A meteor is a “falling star” that is usually seen in the sky at night. A meteor will burn up from frictional heating as it enters the atmosphere. Most of the meteors burn up before they reach the earth. If they do not reach the ground they become meteorites. Meteorites can be seen at a distance of 70 miles from the earth. Meteorites are heavy objects which weigh about 60 tons.

Comets:
Comets are those bodies which revolve round the sun. they are mainly composed of ice and dust. Most comets have three parts which are as under.
i) A solid centre.
ii) A head or round coma, that surrounds the centre and consists of dust particles mixed with frozen water, frozen methane and frozen water, frozen methane and frozen ammonia.
iii) A long tail of dust and gases that escape from the head. Most comets stay near the solar system.
Other characteristics of comets are as under:
• Comet is usually about 10 km or 6 miles across.
• Comets are usually made up of ice and dust.
• Millions of comets are present in the solar system.
• Halley’s comet is the famous example.
• Comets usually move around the sun in the elliptical orbits.

Light Year:
• The distance travelled by light at speed of 186,000 miles per seconds in one year is known as a light year.
• One light year is approximately 9461,000 million kilometres or 5875000 miles. Light year is also used to measure the distance between the galaxies.

Astronomical Unit:
• The distance between the Sun and the Earth is called as Astronomical Unit.
• This unit is also used in the measurement of distances between the heavenly bodies within the solar system.
• The earth is one A.U away from the Sun and the Pluto is 39 A.U away from the Earth.

Black hole:
• Black Hole is a hypothetical region in space which has a big gravitational pull for which no matter or radiation can escape from it.
• Even it is believed that light cannot escape from it. Black Hole usually likes at the centre of galaxy.
Super Nova:
• A Super Nova is an exploding star. At the end of its phase as a Red Giant.
• A heavy star explodes as a Supernova shining briefly as brightly as a thousand million stars.
• Recent Supernova was observed on the night of Feb 23, 1987. This occurred in Large Magellan Cloud.
Nebula:
• Nebula is derived from a Greek word which means “Cloud”.
• In the sky there are clouds like objects, which are classified as Nebulae.
• There are both luminous diffuse nebulae and dark obscuring nebulae over the Milky Way.
• They are made up of dust and gases.
Aurora:
• Aurora or Kutub-i-Raushani is a luminous meteoric phenomenon of electrical character seen in Polar Regions with a tremulous motion and giving forth streams of eight Aurora.
• It is generally believed that the aurora is actually caused by radiation from the Sun-spots.

Solar Wind:
• Solar wind is the stream of electrically charged particles especially protons and electrons, which are emitted by the Sun,
• Predominantly during solar flares and sunspots activity.
• Some of these particles become trapped in the Earth’s magnetic field forming the outer Van Allen radiation belt,
• but some penetrate into the upper atmosphere where they congregate in narrow zones in the region of the Earth’s magnetic poles producing aurora displays.

Cosmic Rays:
• Cosmic Rays are charged particles moving as fast as the speed of light.
• Most of the particles are protons, while some are alpha particles and electrons.
• They travel throughout our galaxy, including the solar system and some strike the earth’s atmosphere.
• They can be detected by instruments on the Earth.
• Nobody knows how cosmic rays are formed. Some of them are formed by exploding stars or supernova and some come from outside our Galaxy.[/QUOTE]

green house effect
Introduction

Green house effect is the process in which the infrared radiation emitted by the atmosphere warms the planet’s surface.

The name comes from an analogy with warming of air inside a green house compared to the air outside the greenhouse.

The greenhouse effect is the global phenomenon in which the temperature of the earth’s atmosphere is radically increasing due the activity of the green house effect .

Greenhouse gases

• Carbon dioxide
• Methane
• Nitrous oxide
• Benzene
• Chlorofluorocarbon

Discovery of the greenhouse

The green house effect was discover by Joseph Fourier in 1829 and first investigated by svante Arrhenius 1896. In addition to earth, mars, and Venus have greenhouse effect.

Mechanism

• The sun radiates solar energy on earth.
• The larger part of this energy (45%) is radiated back into space.
• Greenhouse gases in the atmosphere contribute to global warming by adsorption and reflection of atmospheric and solar energy
The main sources of greenhouse gases due to human activity are:
• burning of fossil fuels and deforestation leading to higher carbon dioxide concentrations in the air.
• Furnace which emit smoke and other pollutant
• Motor vehicle which are responsible for the emission of smoke with poisonous gases.
• Exhaust from auto mobiles is one the major contributor
• Combustion of coal and wood
• Rotten plants contributes through production of gases
• Garbage and industrial exhaust

Importance
• Without greenhouse effect the earth would not be warm enough for human to live
• Without these gases the earth is 60 f colder.