ELECTROMAGNETIC INDUCTION

We have  seen that if electrical current is flowing in a conductor, there is an associated magnetic field created around the wire. In a similar manner, if we move a wire inside a magnetic field there will be an electrical current that will be generated in the wire.

Induction
Current is produced in a conductor when it is moved through a magnetic field because the magnetic lines of force are applying a force on the free electrons in the conductor and causing them to move. This process of generating current in a conductor by placing the conductor in a changing magnetic field is called induction. This is called induction because there is no physical connection between the conductor and the magnet. The current is said to be induced in the conductor by the magnetic field.
One requirement for this electromagnetic induction to take place is that the conductor, which is often a piece of wire, must be perpendicular to the magnetic lines of force in order to produce the maximum force on the free electrons. The direction that the induced current flows is determined by the direction of the lines of force and by the direction the wire is moving in the field.  In the above image the galvanometer (the instrument used to measure current) will indicate when there is current in the conductor.
If an AC current is fed through a piece of wire, the electromagnetic field that is produced is constantly growing and shrinking due to the constantly changing current in the wire. This growing and shrinking magnetic field can induce electrical current in another wire that is held close to the first wire. The current in the second wire will also be AC and in fact will look very similar to the current flowing in the first wire.
It is common to wrap the wire into a coil to concentrate the strength of the magnetic field at the ends of the coil. Wrapping the coil around an iron bar will further concentrate the magnetic field in the iron bar. The magnetic field will be strongest inside the bar and at its ends (poles).

Review

1. If we move a conductor in a magnetic field, a current is induced in the conductor (wire).
2. An AC current in a coil of wire can induce an AC current in another nearby coil of wire.                                                                                                                 source-www.ndt-ed.org

HOW TO MEASURE BLOOD PRESSURE?

Blood pressure measurement

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Blood pressure is a measurement of the force applied to the walls of your arteries as your heart pumps blood through your body.
Your blood pressure can be measured at home, or at your health care provider's office, a fire station, pharmacies, and many other places.

How the Test is Performed

Your arm should be supported, with your upper arm at heart level, back supported, legs uncrossed, and feet on the floor. Your upper arm should be bare, with your sleeve comfortably rolled up.
You or your health care provider will wrap the blood pressure cuff snugly around your upper arm. The lower edge of the cuff should be 1 inch above the bend of your elbow.

• The cuff will be inflated quickly, either by pumping the squeeze bulb or pushing a button. You will feel tightness around your arm.
• Next, the valve of the cuff is opened slightly, allowing the pressure to slowly fall.
• As the pressure falls, the reading when the sound of blood pulsing is first heard is recorded. This is the systolic pressure.
• As the air continues to be let out, the sounds will disappear. The point at which the sound disappears is recorded. This is the diastolic pressure.

Inflating the cuff too slowly or not high enough may cause a false reading. If you loosen the valve too much, you won't be able to determine your blood pressure.
The procedure may be done two or more times.

How to Prepare for the Test

Measuring your blood pressure is best done after you rest for at least 5 minutes.
Do not take your blood pressure when you're under stress, have consumed caffeine or used a tobacco product in the past 30 minutes, or have recently exercised.
Take two or three readings at a sitting, 1 minute apart, while resting in a seated position. When measuring your blood pressure outside of a medical office, it is important to note the time of the readings.
Your doctor may suggest that you do your readings at certain times. A common recommendation is to take your blood pressure in the morning and at night for a week. That way, you will get at least 12 readings to help your doctor make decisions about your blood pressure treatment.

HUMAN DIGESTIVE SYSTEM

OUR HUMAN DIGESTIVE SYSTEM IS MADE MAINLY FROM FIVE PARTS:

• BUCCAL CAVITY
• OESOPHAGUS
• STOMACH
• SMALL INTESTINE
• LARGE INTESTINE

ELECTRIC MOTOR

FLEMING'S LEFT HAND RULE

Fleming's left hand rule

Fleming's left-hand rule (for motors), and Fleming'sright hand rule (for generators) are a pair of visual mnemonics. They were originated by John Ambrose Fleming, in the late 19th century, as a simple way of working out the direction of motion in an electric motor, or the direction of electric current in an electric generator .
When current flows in a wire, and an external magnetic field is applied across that flow, the wire experiences a force perpendicular both to that field and to the direction of the current flow. A left hand can be held, as shown in the illustration, so as to represent three mutually orthogonal axes on the thumb, first finger and middle finger. Each finger is then assigned to a quantity (electric current, magnetic field and mechanical force). The right and left hand are used for generators and motors respectively.

SOURCE: WIKIPEDIA.org/

Ammino acids

Amino acids having both the amine and carboxylic acid groups attached to the first (alpha-) carbon atom have particular importance in biochemistry. They are known as 2-, alpha-, or α-amino acids ;^[4] often the term "amino acid" is used to refer specifically to these. They include the 23 proteinogenic ("protein-building") amino acids which combine into peptide chains ("polypeptides") to form the building blocks of a vast array of proteins.^[5] These are all L-stereoisomers ("left-handed" isomers) although a few D-amino acids ("right-handed") occur in bacterial envelopes and some antibiotics.^[6][7] 20 of the 23 proteinogenic amino acids are encoded directly by triplet codons in the genetic code and are known as "standard" amino acids. The other three ("non-standard" or "non-canonical") are pyrrolysine , selenocysteine (present in many noneukaryotes as well as most eukaryotes), and N-Formylmethionine. For example, 25 human proteins include selenocysteine (Sec) in their primary structure,^[8] and the structurally characterized enzymes (selenoenzymes) employ Sec as the catalytic moiety in their active sites.^[9] Pyrrolysine and selenocysteine are encoded via variant codons; for example, selenocysteine is encoded by stop codon and SECIS element.Codon–tRNA combinations not found in nature can also be used to "expand" the genetic code and create novel proteins known as alloproteins incorporating non-proteinogenic amino acids
Many important proteinogenic and non-proteinogenic amino acids also play critical non-protein roles within the body.Essential amino acids may also differ between species.^[17]
Because of their biological significance, amino acids are important in nutrition and are commonly used in nutritional supplements, fertilizers, and food technology. Industrial uses include the production of drugs, biodegradable plastics and chiral catalysts.


Source::  en.wikipedia.org/wiki/Amino_acid‎

MUSCLE POWER:bats fly using recycled energy

A new study on fruit bats used cutting edge technology to see how these small mammals move through the air. 

According to Dr Nicolai Konow (Brown University, USA), who led the research, "Energy is stored in the triceps tendon, which is used to power elbow extension - in essence, elbow extension happens using 'recycled' energy. State of knowledge, and our results, indicates that bats are unique among small mammals in stretching their tendons, as small mammal limb tendons are thought to be too thick and stiff to be stretched." 
"By combining information about skeletal movement with information about muscle mechanics, we found that the biceps and triceps tendons of small fruit bats are stretched and store energy as the bat launches from the ground and flies vertically," he said
source-zeenews.india.com