No one ever regarded the First of January with indifference. It is that from which all date their time, and count upon what is left. It is the nativity of our common Adam. ~Charles Lamb

HAPPY NEW YEAR !!
www.suryatejreddy.tk

5000-bed health city "Narayana Hrudayalaya-Malla Reddy Hospitals" to come up in Hyderabad

500-bed heart hospital to be operational from Feb 2009

Hyderabad|India|December'2008: Indians are genetically three times more vulnerable for heart disease than Europeans. India needs to perform 25 Lakh heart surgeries annually, and India does approximately 80000 heart surgeries a year across the country. Heart Surgery in India today is not affordable by the common man. To address this problem Narayana Hrudayalaya group of hospitals launched a chain of hospitals under the banner of health cities.

Addressing a press conference,Dr. Devi Shetty, Chairman - Narayana Hrudayalaya said that the Phase-I of health city in Hyderabad will start with 500 bed super specialty heart hospital for adult and paediatric cardiac surgery. The 500-bed heart hospital will be operational by February 2009. This will be followed by 1000 bed cancer hospital. Narayana Hrudayalaya Malla Reddy hospital Campus will cover 40 acres and 5000 beds in three years. The entire infrastructure is created to make high tech health care affordable to the common man. Narayana Hrudayalaya foundation will subsidize the treatment of poor heart patients through its charitable wing.

Narayana Hrudayalaya Health City in Bangalore covers approximately 30 acres of land with world’s largest heart hospital with 1000 beds performing over 30 major heart surgeries a day, surrounded by a 1400 bed super specialty cancer hospital "Mazumdar – Shaw Cancer Centre", Narayana Nethralaya – a super specialty eye hospital with an infrastructure to perform 500 eye surgeries daily and SPARSH orthopaedic super specialty hospital. Narayana Hrudayalaya health city in Bangalore is an academic institution in the process of becoming a university. Our group is in the process of creating 5000 bed health cities each at Jaipur, Calcutta, Ahemedabad, Jamshedpur and Bhuveneshwar, Dr. Shetty added.

LET'S TALK ABOUT THE RC CIRCUIT!

I feel better in this semester because no stress has yet developed except the bakwas lab record writing.
But still if you want to impress the lab people i have some interesting things to tell you now.

Most of you know that RC circuit acts as high pass when output is taken at the resistor.And low pass when at the capacitor.

Another function of this awesome thing is as an integrator and a differentiator.Yeah!you got it is the same what you read in maths since three years.As you are reading the PDC book or at least attended the lab(I was thrown out last time,but still have an idea).You have seen that for high pass when the time constant (RC less less thanT)
The output is a peak which almost goes to zero before the input does.When you still decrease the RC value the peak goes closer and closer near the discontinuity.So it is forming an impulse near the step rises and going down fast(super duper fast)which is an approximate impulse

Well you have already studied in signals and systems that the derivative of a step function is an impulse.Here the input is a square wave which is a combination of step functions.
So for every step there is an almost impulse output.

In a way you can say the RC high pass is differentiating the input.It not only differentiates the step kind of waves but any general wave up to certain limitations.

Still I have to tell you how it works as an integrator......cont.. tomorrow(this is not an online course and I am not paid..... at least this much is tooooo much...)

Advantages of FM

1. The depth of modulation of the frequency modulated wave in FM is independent of amplitude,whereas in the AM it is independent on these parameters.
2. Because of the frequency allocation,there is less channel interference than in the AM.
3. In FM,the noise can be reduced by increasing the frequency deviation.In the AM,we do not have this one.
4. In FM,we can reduce the large noise by increasing the signal-to-noise ratio.
5. The transmitter in FM can operate at higher frequency such as VHF and UHF ranges so that,radius of reception is limited.
   

HOW YOU GET ONLY SOME FREQUENCIES IN THE EXPERIMENTS OF AMPLIFIERS IN LAB?

When we did the CE amplifier experiment or JFET or multistage amplifier experiment,we see that there is a lower 3dB frequency and upper 3dB frequency.
Have you ever thought why one side it is low pass and other side it is high pass?

ACTION OF HIGH PASS

Now when you use a coupling capacitor after the source the biasing resistance,input impedance of amplifier form a net resistance.Which makes the input circuit look like a high pass circuit.
So now we conclude that the amplifier attenuates low frequencies and allows mid band frequencies.

Now when the frequency range crosses the mid-band then these blocking capacitors act as short circuits.
Then what the heck can attenuate the frequencies?.
The answer is the internal capacitances of the transistors

INTERNAL CAPACITANCES

Now the question is why did these capacitances didn't come into picture for lower frequencies?
This may be explained like this,
Now there are two PN junctions in the BJT or 3 In FET
When there is sudden change in the voltage from forward to reverse it takes some time to come into its nature.Suppose there is a forward bias initially and there is an instantaneous change from forward to reverse has happened.Now there are moving carriers which have to be stopped and they have to move in opposite direction. So it takes some time.

Suppose your going to your home and somebody calls you from the back then you can't just vanish and go to him,you have to run/walk.It's the same way here.

Now when you increase the frequency the time taken for recovery is not satisfied.So some of the charges get stored which is a capacitive effect.
Now for low frequencies there is a lot of time left after the recovery.


ACTION OF LOW PASS

All the internal capacitance are parallel to the internal resistances.
So the output circuit looks like a low pass filter,which attenuates higher frequencies and allows mid-band frequencies.
I am glad to say that i have reached an explanatory level of my subject......

Properties of Java Language

The people who invented Java wanted to design a language which can provide solution to the problems faced in modern programming.
The following are the various features in Java.
1. Object-oriented
2.Compiled and Interpreted
3.Platform-independent and Portable
4.Distributed
5.Robust and secure
6.Familiar,simple and small
7.Multithreaded and interactive
8.Dynamic and extensible
9.High performance

Modulation

Modulation is one of the important terms in basic communication systems.
Modulation is defined as "Changing the characteristics of a signal",called carrier which is varied in accordance with the instantaneous value of another signal called Modulating signal.
The signal resulting from the process of modulation is called modulated signal.The modulation is the process of placing the message signal over the carrier signal,which is useful for suitable transmission.

Types of Modulation

Modulation can be divided into two basic categories :

i) Pulse Modulation
ii)Continuous wave modulation

i)Pulse Modulation
Modulation is the process of changing the characteristics of the signal according to the modulating signal.When the carrier wave is a pulse type wave form,the modulation is known as pulse modulation.

Examples of pulse modulation are pulse amplitude modulation,pulse width modulation and pulse position modulation.

ii)Continuous Wave Modulation
When the carrier signal is in the form of continuous wave,this type of modulation is known as continuous wave modulation.

Examples are amplitude modulation, angle modulation and frequency modulation.

3D coordiante sytems

In a 3D Cartesian coordinate system, a point P is referred to by three real numbers (coordinates), indicating the positions of the perpendicular projections from the point to three fixed, perpendicular, graduated lines, called the axes which intersect at the origin. Often the x-axis is imagined to be horizontal and pointing roughly toward the viewer (out of the page), the y-axis is also horizontal and pointing to the right, and the z-axis is vertical, pointing up. The system is called right-handed if it can be rotated so that the three axes are in the position as shown in the figure above. The x-coordinate of of the point P in the figure is a, the y-coordinate is b, and the z-coordinate is c.


To define a cylindrical coordinate system, we take an axis (usually called the z-axis) and a perpendicular plane, on which we choose a ray (the initial ray) originating at the intersection of the plane and the axis (the origin). The coordinates of a point P are the polar coordinates (r, f) of the projection of P on the plane, and the coordinate z of the projection of P on the z-axis. The coordinate r is always positive and the range of f is from 0 to 2p (360o).

To transform from Cartesian to cylindrical coordinates and vice versa, we use the transformation equations

x = r cosf, y = r sinf, z = z,

r = (x2 + y2)1/2, f = tan-1(y/x), z = z.


To define spherical coordinates, we take an axis (the polar axis) and a perpendicular plane (the equatorial plane), on which we choose a ray (the initial ray) originating at the intersection of the plane and the axis (the origin O). The coordinates of a point P are the distance r from P to the origin; the angle q (zenith) between the line OP and the positive polar axis; and the angle f (azimuth) between the initial ray and the projection of OP onto the equatorial plane. The range of f is from 0 to 2p (360o)., and the range of q is from 0 to p (180o).

To transform from Cartesian to spherical coordinates and vice versa, we use the transformation equations

x = r sinq cosf, y = r sinq sinf, z = r cosq,

r = (x2 + y2 + z2)1/2, q =tan-1(z/(x2+y2)1/2), f = tan-1(y/x).