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Fire is a chemical reaction that occurs very quickly, and in the process, gives off heat and light.

Three things are necessary for this reaction to occur- fuel, oxygen, and heat.

Fuel whether it is paper or wood-by itself will not catch fire. It is only when the fuel is heated, and becomes hot enough, that the oxygen in the air combines freely with it to burst into flames.

The reason, fire is hot is because it releases a lot of energy that has been stored in fuel. For example, energy from sunlight is stored in the wood that is used as fuel.

When energy is released very quickly, heat and light are produced.

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short series – 8 SKIN


The skin has two primary layers: the epidermis (outer) and the dermis (inner). The epidermis has two important sublayers the stratum germi nativum and the stratum corneum. The epidermis is made up of cells called keratinocytes; these cells make up the epithelial tissue.

It is in the epidermis layer where blisters and calluses can form. Blisters occur when friction such as what might develop between the skin and the inside of a shoe-causes layers to separate within the epidermis or between the epidermis and the dermis.

As these layers separate, tissue fluid may build up, leading to a blister. While blisters often result because of fric tion, calluses result from pressure. When exposed to increased amount of pressure, mitosis will occur at a rapid rate, causing the epidermis to thicken.


Glucose, Fat, and Protein Metabolism

Glucose, Fat, and Protein Metabolism

In the muscles and other tissues, cortisol increases the breakdown of pro tein into amino acids.

Those amino acids are used to produce additional glucose (via a metabolic pathway called gluconeogenesis) in the liver.

Cortisol also conserves glucose for the brain and spinal cord by blocking the actions of insulin (which will be discussed later in this chapter) inhibiting glucose absorption into other tissues.

Cortisol also stimulates the release of fatty acids and glycerol from adipose tissue.

Glycerol is used in gluconeogenesis, while fatty acids are made available for energy to other tissues to preserve glucose for the brain.

Cortisol reduces protein reserves everywhere except in the liver.

As proteins continue to be broken down in muscles and in other tissues, blood levels of amino acids rise.

The additional amino acids are used for gluco neogenesis, glycogen formation, and protein synthesis in the liver.



Feathers, are important parts of a bird’s flying equipment’. A bird’s tail feathers are used for lifting, steering, and breaking, and these are perfectly symmetrical, to allow a balanced and smooth flight.

Along the sides of a bird’s feathers are barbs, which if separated, look like a fringe, or even like the threads that stick out from the edge of a piece of unstitched cloth. Since these barbs end in hooks, they hook on to one another efficiently, making a strong, but light flying wing.

There here are two sources of feather colour- pigments, and the physical structure of the feather. Many feathers are coloured by a combination of these features. Pigments are chemical compounds that absorb certain wavelengths of light while reflecting others. The colours you see are those reflected back. Feathers coloured by pigments, range from crow black to canary yellow, and cardinal red.

Many colours, such as blue, are a result of feather structure. When light hits these feathers, it hits microscopic structures on the feather that act as prisms to reflect a colour.
No blue pigment is known in birds. Shimmering iridescent colours such as those found in peacocks, are caused by special structures, air bubbles, or films on feather surfaces.

These modifications interfere with the bending and scattering of light to strengthen some wavelengths, and cancel out others.


Keep Your Mind Alive During Lecture

Some instructors are good lecturers, others not so much. But whatever your circumstance, you can do a lot on your end to get the maximum benefit out of attending lecture:

Write notes in your own words. Listen to what your instructor is saying and write your own notes. Writing your own notes is very different from just sitting there and writing down whatever the instructor says or writes on a board. If you’re listening and writing things in your own words, you’re processing the information as you go.

Take notes on interesting stories and anecdotes. Instructors often tell stories and give examples to show the relevance of the information they’re presenting. They don’t usually write down these stories, how ever, so many students don’t write them down either. If the instructor tells a good one that helps you grasp the concept they’re talking about, jot down a few notes about it in the margin of your notes. When you’re studying later, these side notes may help you recall the topic.

Sit in the best place for you in lecture. Usually, the front is best. It’s too easy to get distracted and tune out in the back. However, if you’re some one who gets sleepy and might need to move around a little to wake up, then try an aisle seat. If you get sleepy, you can get up and take a short walk to the rest room. It’s better to get up and move than to miss half of lecture because you took a nap.

Ask questions when you don’t understand. If you’re prepared for class and following the lecture but something doesn’t make sense to you, then ask about it. Chances are if you don’t get it, someone else doesn’t either.

Be in good physical shape for class. Get enough sleep, exercise, and healthy food so that you’re ready to participate.



1:-You have a finite amount of willpower each day because to exercise your willpower you need energy in the form of oxygen and glucose. That’s why it’s harder to say ‘no’ when you are tired or not feeling yourself.

2:-A thought is a physical pathway in the brain. The more you have that thought, the more you groove and strengthen that path and the easier it is to have it again and again.

3:-Even if you consider yourself a creative right brained person, your brain will increase blood circulation to the left of your brain side every 90 to 120 minutes, giving you a greater ability during those times to think linearly.

4:-Your brain only weighs about 3lbs, yet the greedy bastard uses between 20% and 25% of your energy supplies each day, so make sure you stay hydrated and eat high quality food.

5:-Speaking of large numbers, there are approximately 1.1 trillion cells and 100 billion neurons in the average human brain.

6:-A piece of brain tissue the size of a grain of sand contains approximately 100,000 neurons and 1 billion synapses.

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A change with which you are quite familiar is the rusting of iron. If you leave a piece of iron in the open for some time, it acquires a film of brownish substance.

This substance is called rust and the process is called rusting. Iron gates of parks or farmlands, iron benches kept in lawns and gardens, almost every article of iron, kept in the open gets rusted. At home you must have seen shovels and spades getting rusted when exposed to the atmosphere for some time.

In the kitchen, a wet iron pan (tawa) often gets rusted if left in that state for some time. Rust is not iron. It is different from iron on which it gets deposited.

RUSTING OF IRON:- Let us get back to rusting. This is one change that affects iron articles and slowly destroys them. Since iron is used in making bridges, ships, cars, truck bodies and many other articles, the monetary loss due to rusting is huge.

For rusting, the presence of both oxygen and water (or water vapour) is essential.



Scanning Electron Microscope

SEM generally has a lower resolving power than the TEM. It is very useful for providing three-dimensional images of the surface of microscopic objects.

In this electrons are focused by means of lenses in to a very fine point. The interaction of electrons with the specimen results in the release of different forms of radiation (eg secondary electrons) from the surface of the specimen. These radiations are then captured by an appropriate detector, amplified and then imaged on a television screen.

Other important techniques in EM include the use of ultra thin sections of embedded material; a method of freeze- drying specimen, which prevents the distortion caused by conventional drying procedure; and the use of negative staining with an electro dense material such as phosphotungstic acid or Uranyl salts. These heavy metal salts provide enough contrast to detect the details of the specimen.



According to various international studies, the world’s most popular color is blue. Though some researchers also suggest that red and green are a close second and third respectively.

Pink is the palliative color. Apparently, it suppresses anger and anxiety due to its calming effect.

The safest car color was determined to be white.  Based on studies, it is the most visible color under all conditions except snow. Though surprisingly, lime-yellow is the most visible color on the road. 

Researchers says that red and yellow are the most appetizing colors. Having said that, they advice not to paint your kitchen yellow if you’re on a diet.

Researchers says that red and yellow are the most appetizing colors. Having said that, they advice not to paint your kitchen yellow if you’re on a diet.

Research shows that mosquitoes are attracted to dark colors especially blue. 

The color yellow can cause nausea, so it is avoided in airplanes. Also, pure bright yellow is believed to be the most irritating color due to its excessive stimulation to the eye.

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Festival of colours and the Festival of spring.

Holi celebrates the arrival of spring, the end of winter.

where people smear each other with colours


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