My Science School

Our world is full of mechanics that help us use things, go places, and communicate. Engineers help make all this possible. Here are just a few types of engineers and what they do.

Architectural engineers

Architectural engineers develop better ways of building homes and other buildings. They also find ways to make buildings taller. They apply the latest scientific knowledge and technologies to the design of buildings. Architectural engineering as a relatively new licensed profession emerged in the 20th century as a result of the rapid technological developments. 

Chemical engineers

Chemical engineers design ways to end pollution. They create drugs to fight cancer and other illnesses, too. Chemical engineers work mostly in offices or laboratories. They may spend time at industrial plants, refineries, and other locations, where they monitor or direct operations or solve onsite problems. Nearly all chemical engineers work full time.

Civil engineering

Civil engineering is the oldest kind of engineering. Civil engineers design bridges, subways, roads, dams, and canals. Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering.

Electrical engineers

Electrical engineers design equipment that produces electric power and sends it to our homes. They also design computer circuits and robots. Electrical engineers work in a very wide range of industries and the skills required are likewise variable. These range from circuit theory to the management skills of a project manager. The tools and equipment that an individual engineer may need are similarly variable, ranging from a simple voltmeter to sophisticated design and manufacturing software

Materials engineers

Materials engineers work out how to make the produces we use better. They develop new materials for making anything from hand tools to huge trains. They also find new ways to use the materials we already have.

Mechanical engineers

Mechanical engineers design new machines. Some mechanical engineers invent better ways of heating and cooling homes and buildings. The mechanical engineering field requires an understanding of core areas including mechanics, dynamics, thermodynamics, materials science, structural analysis, and electricity.

In many ways, engineers are helping to design the future.

 

Picture Credit : Google

With a click and a whirr, a robot keeps busy in the factory. It joins steel panels together. All day long it works on brand-new cars.

Some robots push a metal pin called a rivet through metal sheets to join the pieces together. Others are welders. They heat the edges of the metal very quickly so that they melt and join together.

There are no humans working these robots. These robots work by themselves.

How are robots able to join the parts correctly every time? First, a human teaches the robot to do the job. As the human moves the different parts of the mahine in and out, up and down, reaching out and twisting around, every movement is recorded by the robot’s microprocessor. Now the robot has all these movements in its memory. It knows exactly what to do every time a car is put in front of it. As long as the cars are put in exactly the same place each time, the robot will move into action and carry out exactly the right movements for riveting, welding, or even spray-painting.

 

Picture Credit : Google

Tall trees in the forest sway in the wind. So do tall skyscrapers in the city but you just don't notice it as much. So how do these very tall buildings stay up?

The walls of a skyscraper are made of stone, concrete, glass, or metal. Under the walls is a frame of concrete or steel. This frame is strong enough to hold up the walls and floors. But it can also bend very slightly in the wind-like trees do. A tall tree has deep roots that hold the trunk and branches. Tall buildings have deep foundations. The foundation holds the steel girders in the ground.

The builders dig down until they find solid rock to build. The builders dig down until they find solid rock to build the foundation on. If there is no rock and the ground is soft, the basement is built on piles. Piles are deep holes bored into the ground. The holes are filled with steel and concrete. This gives the building a sturdy base to rest upon.

 

Picture Credit : Google

Thanks to bridges, rivers and lakes will not interrupt a journey. People build bridges to make it easier to cross rough land or water. There are thousands of bridges in the world, but only five basic kinds: beam, arch, suspension, cantilever, and cable-stayed bridges.

Do you think bridges could be made out of glass? Inventors are working on this idea now. Concrete used in bridges is worn down by salt, ice, and wind. The steel used to make the concrete stronger often rusts. But a special glass called fibreglass is very strong. When glass fibres are held together by a type of "glue" ice, and wind. The steel used to make the concrete stronger often rusts. But a special glass called fibreglass is very strong. When glass fibres are held together by a type of "glue" called resin, they become stronger than steel or concrete. Fibreglass is also lightweight and can be easily shaped.

Beam bridge: This can be made of wood, steel, or concrete.

Arch bridge: A beam bridge can break easily in the middle. But a curving arch helps to carry the load on the bridge.

Suspension bridge: The roadway is suspended, or hung, from long steel cables. This type of bridge can be much longer than other types.

Cantilever bridge: One or more independent beams joined by a centre span make a cantilever bridge.

Cable-stayed bridge: This is one of the newest kinds of bridge designs. It takes less concrete or steel than a beam bridge. And it fits across narrow rivers better than a suspension bridge.

 

Picture Credit : Google

People have been using bridges to cross water for thousands of years. The earliest bridges were tree trunks. A tree growing near the bank was chopped down so that it fell across the river. Then people walked across on it. In the jungles of South America, for a long time people have made bridges out of the vines that grow there.

The ancient Romans built arched bridges out of stone. Many of them are still used today! Some bridges are still made in the same way,

Bridge-builders build strong columns, called piers, on each side of the arch. Then a strong frame is made out of wood between the piers. The arch stones are laid on top of the frame. Each stone is wedge-shaped-it is wider at the top than at the bottom. The last stone, which fits in the middle of the arch, is called the keystone. When the keystone is pushed into place, the wooden frame is taken away.

The arch will then stay in place by itself. Each stone is pressing against the next, so they hold one another up.

 

Picture Credit : Google

You are building a road but a mountain is in the way. Could the road be built over the mountain? That would be rough travelling. What about going around? That would take longer-to build it and to drive on it. What about digging a tunnel? A tunnel is the shortest route, and there are many ways to build one.

Tunnels built through hard rock are usually blasted. Workers use explosives to blast each section of rock. Then they build supports in the newly opened part of the tunnel to keep rock from falling in.

Huge boring machines tunnel through clay or soft rock. As steel tubes dig through the ground, the machine "swallows" the earth and rock. The earth is dumped at the back of the machine the tunnel opening where trucks can haul it away. Reinforced concrete or steel is used to make the floor, walls, and roof of the tunnel.

Cut-and-cover tunnels are built close to the surface. Workers dig a deep trench. Then they build a floor, walls, and roof of reinforced concrete. When the concrete has hardened, the area around the concrete is filled to street level.

The mountain is no longer in the way. You simply drive right through it.

 

Picture Credit : Google

What is your home like? Are the walls made of brick, or wood, or concrete? Are the windows large or small? Does it have a wood shingle roof or a tile roof?

Today, most houses are made of wood, brick, and glass. The kind of materials used depends on the size of the house, its design, and the climate.

Many houses use a lot of wood. Wood is used to make the frame of the house and the frames between the walls. Sheets of wood are used for the floors and roof.

The roof is covered with tar paper and then tiled. In warm climates, ceramic tiles are used to keep the house cool.

In snowy climates, the roof slopes to let the heavy snow slide off.

On the outside, many homes use aluminium or vinyl walls because it doesn't need to be painted. They can withstand cold, hot, and windy weather. Bricks also make very sturdy walls and are usually easy to get. Bricks come in many colours, too.

Large glass windows let in lots of sunshine.

Gutters are made of aluminium or plastic. They keep the water running off the roof from leaking into the house.

 

Picture Credit : Google

Every day, workers in factories make the clothes we wear, the toys we play with, and the food we eat. The workers are the people on the assembly line and the people who pack and ship the products. But there are other workers involved in making products and food, too.

Does your cereal stay crispy in milk? People called food chemists develop and improve foods. They test new coatings or glazes to keep cereal crispy in milk. They add vitamins and minerals to make it healthier. And they test different ways of cooking and packing to improve the taste or quality.

Agricultural engineers help design the machines used to make a new breakfast cereal. They might work with the food chemists to decide how the cereal will be made.

Quality technicians test the food for freshness. They also make sure the taste and texture of the food stay the same during production.

Plant technicians work with the people who buy the ingredients. Quality ingredients are important to make quality food. Plant technicians also work on improving how food is shipped to shops.

 

Picture Credit : Google

When you ride your bike, you wear a helmet to protect your head. If you play football or other sports, you may wear helmets or shin guards made of plastic, But did you ever think you would wear plastic clothes?

Soon after plastics were invented, scientists learned how to make some of them into wearable fabric. For example, nylon is an artificial fabric made from plastic Nylon is lightweight and waterproof. That's why it is a popular fabric for outdoor clothes. When it's cold outside and the wind is blowing hard, do you put on a waterproof jacket? If you do, the chances are you're wearing plastic.

The lining of your jacket probably contains polyester. Polyester is another artificial material. It is often used in coat linings because it is durable and warm.

Many other things we wear are made from artificial fabrics. Look at your boots. Do the soles look like rubber? Today most “rubber" is made from nylon mixed with other artificial materials. Like rubber that comes from the rubber tree, it is good at keeping water out.

 

Picture Credit : Google

Let your imagination go. Snap brick after brick together and create a castle, or a spaceship. Children have played with building bricks for many years.

As you are making your cities and ships, do you ever wonder how plastic building pieces are made? They are made of a strong, tough, long-lasting plastic. Each building piece begins as a bunch of plastic pellets. The plastic pellets are heated to 230 °C. When they melt, they are like bread dough. Moulding machines press this "dough" into different shapes and pieces.

The parts fall into bins at the end of each machine. Robots collect the full bins. They are then labelled and placed in a warehouse.

Different departments put different building kits together. First, they order the pieces they need from the factory. Then, workers in each department seal the pieces in small plastic bags. The bags are sorted into boxes for the building kits. Other machines make the labels and boxes for each set.

For some model designers, work is play! Many get to play with plastic building bricks all day. Their job is to make designs for displays at toy fairs and exhibitions around the country. Sometimes these designs are over 2 metres high! Children love to play with toy bricks, too.

 

Picture Credit : Google

Look at your toys. What are they made of? Many toys are made of plastic. Plastic is easily shaped, and it lasts a long time. Hard plastic helmets protect us when we ride bikes or play sports. Rubber-like plastic is used to make balls. Soft plastics are used to make dolls. And plastic can be recycled to make long-lasting benches and picnic tables.

Plastic is not dug from the ground like metal ore. It is made from chemicals in crude oil. The chemicals in plastic can be heated so that they soften or melt. Then they are shaped into different items.

Sometimes, the chemicals are poured as liquid into moulds. Once they cool, the plastic becomes solid.

A softer, movable plastic called vinyl is used to make some toys. The moulds used to make these parts are spun around so that the vinyl clings to the inside walls. The parts harden as they bake in an oven.

 

Picture Credit : Google

Look around you. What objects do you see that are made of metal? The doorknob may be made of iron or brass. Your fork and spoon may be made of steel or silver. The ring on your mum’s or dad’s finger may be made of gold or silver. Metals are all around us. But where do they come from?

You can’t dig metal out of the ground. But the ore, or mineral, that metal comes from is found underground. Ore is made of metal joined with rocks. Ore is metal in its raw form.

To get metals out of the ground, miners first dig out the ore. The ore is taken to a factory where heat is used to separate the metal from the ore. This process is called smelting. The ores are dumped into a blast furnace and heated to over 1600 °C. The metals in the ores melt and pure liquid metal sinks to the bottom. The rest of the ore is waste material called slag.

The liquid metal is poured into moulds until it hardens. The bars of hardened metal are called ingots.

The ingots are ready to be rolled, pressed, or moulded into the shapes of the things we use.

 

Picture Credit : Google

The next time you drink your favourite juice, look carefully at the cup. Is it made of glass? Look at the windows in your house. They are made of glass. Marbles are usually made of glass, too. Where does glass come from? Actually It’s mostly sand!

Glass is made by mixing sand with chemicals. The mixture is heated above 1430 °C. Coloured glass is made by adding chemicals. To make the sheets of glass you see in windows, liquid glass is poured onto melted tin and pulled onto rolled when it sets.

Glass containers were first made about 4,000 years ago. The liquid glass was built up around a piece of clay. When the glass hardened, the clay was removed. About 2,000 years ago, someone discovered that a gob of liquid glass on the end of a tube could be blown into a hollow shape – like your juice glass!

Today, most glass items are made by machines. Gobs of liquid glass are pushed into moulds. Others are formed by people who use fire to heat the glass and make it soft enough to blow.

 

Picture Credit : Google

Look very closely at a piece of thread Do you see the fibres in it? Fibres are the raw materials of fabric.

Many of our clothes are made of plant fibres. Cotton is the most widely used natural fiber. Its fibres come from the seed pods of the cotton plant. A carding machine makes the tangled strands of cotton all lie in the same direction. Then the strands are twisted and stretched to make cotton thread. When it is woven into cloth, cotton is light and cool to wear.

Linen comes from the stem of the flax plant. After the plants are cut, they are soaked in water to loosen the fibres in the stems. Machines then clean the fibres and spin them to make linen thread. Linen is woven into very fine cloth. It is cool to wear, even on a hot day. Silk comes from a caterpillar called a silkworm. It makes silk fibres. It grows by eating leaves from the mulberry tree. Then it spins a cocoon around itself, using one very long strand of fine silk thread. Silk thread is made by twisting the strands of several cocoons together. Pure silk cloth is thin and fine, but very strong.

We get wool from animals. Most wool comes from sheep. The farmers usually shear the sheep once a year. The fibres are straightened to make yarn. Pure wool can be knitted or woven to make warm clothes.

 

Picture Credit : Google

What do you think the first storage containers were made of? They may have been made of animal skins or wood on even stone. But around 8,000 B.C., people learned to dig clay from the ground, mold it into a shape, and let the clay dry out until it was hard. The clay containers worked well for storing dry things. But they were not watertight.

The Chinese discovered how to make clay watertight. If clay is heated to a high enough temperature for a long time, it changes chemically. Clay is made of many different minerals. Dirt and mud have some of these minerals, but not enough for the chemical change needed. The chemical changes make the clay stronger and watertight. Modern pottery ovens, or kilns, use gas, oil, or electricity to get the heat needed. The temperature must be about 1200 °C for 14 to 30 hours. This process is called firing.

In modern factories, the clay is shaped by a machine or in a mold. When the clay has been fired, it is ready for glazing. Glazing means covering the clay with a thin layer of liquid glass. The object is then fired again, and the result is a clay object covered with shiny glass. It is watertight and ready to use.

 

Picture Credit : Google