Monday, September 29, 2014

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Lecture 1: XHTML and CSS Tutorial - 1 - Downloading a Text Editor

about lecture:
Prof. Bucky Roberts
Visit my website at https://buckysroom.org/ for all of my videos and tutorials!

Facebook - http://www.facebook.com/pages/TheNewB...

LECTURE CONTENTS:
Downloading a Text Editor - Creating our First Webpage - body and headers - Paragraphs and Line Breaks - Bold, Italics, and Comments - Adding Links to our Webpage - Creating a Link Within a Web Page - Email Links and Tool Tips - Adding Images to the Webpage - Resizing Images - Tables - Table Headers and Movie Stars! - colspan & Annoying People - Table width, cellpadding, and cellspacing - Lists - Intro to CSS
RGB Color and Line Spacing - font-weight & font-style - text-align and Changing Background Color - Background Images - Padding - Border - Margin - Width & Height - Styling Links - Styling Tables - Background Images - Style More Than One Elements & Span! - div - Styling Using Classes - IDs - Child Selectors - Pseudo Elements - External Style Sheets - Overriding Styles - Absolute Positioning - Relative Positioning - Fixed Positioning - Max Width & Height - Introduction to Forms - Check Boxes & Radio Buttons - Drop Down Lists - Text Areas - Passwords & Upload Buttons - Submitting Forms - How to Publish Your Website! 
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Sunday, September 28, 2014

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aerospace engineering full course online by nptel and IIT's.

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Saturday, September 27, 2014

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Basic Principle Of Alternator

A.C. generators or alternators (as they are usually called) operate on the same fundamental principles of electromagnetic induction as d.c. generators. They also consist of an armature winding and a magnetic field. But there is one important difference between the two. Whereas in d.c. generators, the armature rotates and the field system is stationary, the arrangement in alternators is just the reverse of it. In their case, standard construction consists of armature winding mounted on a stationary element called stator and field windings on a rotating element called rotor.

The details of construction are shown in Fig.

basic+principle+of+alternator
alternator


The stator consists of a cast-iron frame, which supports the armature core, having slots on its inner periphery for housing the armature conductors. The rotor is like a flywheel having alternate N and S poles fixed to its outer rim. The magnetic poles are excited (or magnetised) from direct current supplied by a d.c. source at 125 to 600 volts. In most cases, necessary exciting (or magnetising) current is obtained from a small d.c. shunt generator which is belted or mounted on the shaft of the alternator itself. Because the field magnets are rotating, this current is supplied through two sliprings. As the exciting voltage is relatively small, the slip-rings and brush gear are of light construction. Recently, brushless excitation systems have been developed in which a 3-phase a.c. exciter and a group of rectifiers supply d.c. to the alternator. Hence, brushes, slip-rings and commutator are eliminated.

When the rotor rotates, the stator conductors (being stationary) are cut by the magnetic flux, hence they have induced e.m.f. produced in them. Because the magnetic poles are alternately N and S, they induce an e.m.f. and hence current in armature conductors, which first flows in one direction and then in the other.

Hence, an alternating e.m.f. is produced in the stator conductors
(i)whose frequency depends on the number of N and S poles moving past a conductor in one second and
(ii)whose direction is given by Fleming's Right-hand rule.



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Aerospace engineering - Space Flight Mechanics

Aerospace engineering- Space Flight Mechanics

Lecture summary:
Space Flight Mechanics by Dr. Manoranjan Sinha, Department of Aerospace Engineering, IITKharagpur.

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Aerospace engineering - Introduction to Aerodynamics

Aerospace engineering - Introduction to Aerodynamics

Lecture summary:
Introduction to Aerodynamics by Dr. K.P. Sinhamahapatra, Department of Aerospace Engineering, IITKharagpur.

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Aerospace engineering - High Speed Aero Dynamics

Aerospace engineering - High Speed Aero Dynamics

lecture summary:
High Speed Aero Dynamics by Dr. K.P. Sinhamahapatra, Department of Aerospace Engineering, IITKharagpur.
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Aerospace engineering - Optimal Control, Guidance and Estimation

Aerospace engineering - Optimal Control, Guidance and Estimation


Lecture summary:
Optimal Control, Guidance and Estimation by Dr. Radhakant Padhi, Department of Aerospace Engineering, IISc Bangalore.

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