How does the Brain work

Lesson 1

Actually our scientists are still unable to give proper description about the working process of BRAIN.

The human brain is perhaps the most complex of organs, boasting between 50-100 billion nerve cells or neurons that constantly interact with each other. These neurons ‘carry’ messages through electrochemical processes; meaning, chemicals in our body (charged sodium, potassium and chloride ions) move in and out of these cells and establish an electrical current.

Rodrigo Quian Quiroga Professor of Leicester Bioengineer University publish an article called Nature Reviews Neuroscience. In the article, Prof. Quian Quiroga and co-author Dr. Stefano Panzeri discuss new methodologies that are enabling scientists to better understand how our brain processes information.

“The human brain typically makes decisions based on a single stimulus, by evaluating the activity of a large number of neurons. I don’t get in front of a tiger 100 times to make an average of my neuronal responses and decide if I should run or not. If I see a tiger once, I run” said by Prof. Quian Quiroga

He also add

“A major challenge of our days is (thus) to develop the methodologies to record and process the data from hundreds of neurons and developing these is by no means a trivial task”.

“Our brains are able to create

very complex processes – just imagine the perfect harmony with which we move different muscles for normal walking – thousands of neurons are involved in this and to determine the role of each is complicated”.

In review paper he discusses about two things. One is ‘decoding’ and ‘information theory’.

‘Decoding’ essentially helps determine what must have caused a particular response (much like “working backwards”). Thus, the response of a neuronal population is used to reconstruct the stimulus or behaviour that caused it in the first place. ‘Information theory’, on the other hand, literally quantifies how much information a number of neurons carry about the stimulus.

He said “together, the two approaches not only allow scientists to extract more information on how the brain works, but information that is ambiguous at the level of single neurons, can be clearly evaluated when the whole ‘population’ is considered”

The review is an asset for anyone involved in the field, as it carefully considers and evaluates the two statistical approaches, as well as describes potential applications.

Working process of AC

We all are know about ac. That it control the heat. But how? lets see that..

Air conditioner (AC) are use to control heat. Refrigerator and AC work in same prices.

Air conditioners use chemicals that easily convert from a gas to a liquid and back again. This chemical is used to transfer heat from the air inside of a home to the outside air.

A compressor, a condenser and an evaporator is the part of AC. The compressor and condenser are usually located on the outside air portion of the air conditioner. The evaporator is located on the inside the house, sometimes as part of a furnace. That's the part that heats your house.

Pic of AC

The working fluid arrives at the compressor as a cool, low-pressure gas. The compressor squeezes the fluid. This packs the molecule of the fluid closer together. The closer the molecules are together, the higher its energy and its temperature.

The working fluid leaves the compressor as a hot, high pressure gas and flows into the condenser. If you looked at the air conditioner part outside a house, look for the part that has metal fins all around. The fins act just like a radiator in a car and help the heat go away, or dissipate, more quickly.

When the working fluid leaves the condenser, its temperature is much cooler and it has changed from a gas to a liquid under high pressure. The liquid goes into the evaporator through a very tiny, narrow hole. On the other side, the liquid's pressure drops. When it does it begins to evaporate into a gas.

As the liquid changes to gas and evaporates, it extracts heat from the air around it. The heat in the air is needed to separate the molecules of the fluid from a liquid to a gas.

The evaporator also has metal fins to help in exchange the thermal energy with the surrounding air.

By the time the working fluid leaves the evaporator, it is a cool, low pressure gas. It then returns to the compressor to begin its trip all over again.

Connected to the evaporator is a fan that circulates the air inside the house to blow across the evaporator fins. Hot air is lighter than cold air, so the hot air in the room rises to the top of a room.

There is a vent there where air is sucked into the air conditioner and goes down ducts. The hot air is used to cool the gas in the evaporator. As the heat is removed from the air, the air is cooled. It is then blown into the house through other ducts usually at the floor level.

This continues over and over and over until the room reaches the temperature you want the room cooled to. The thermostat senses that the temperature has reached the right setting and turns off the air conditioner. As the room warms up, the thermostat turns the air conditioner back on until the room reaches the temperature.

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