Protected: Windows Mail Backup and Restore (VISTA)
Posted on March 8, 2008
Filed Under Computer (HW & SW), Knowledge Base | Comments Off
Download Free Books
Posted on January 18, 2008
Filed Under Downloads, Electrical Engineering | Leave a Comment
a) Unbounding the Future: The Nanotechnology Revolution
Eric Drexler and Chris Peterson, with Gayle Pergamit
William Morrow and Company, Inc., New York
b) Modern Signal Processing
by Various Authors.
Virus
Posted on January 14, 2008
Filed Under Computer (HW & SW), Downloads, Knowledge Base | Leave a Comment
What’s a Computer Virus?
A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user. However, the term “virus” is commonly used, albeit erroneously, to refer to many different types of malware programs. The original virus may modify the copies, or the copies may modify themselves, as occurs in a metamorphic virus. A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or the Internet, or by carrying it on a removable medium such as a floppy disk, CD, or USB drive. Additionally, viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer. Viruses are sometimes confused with computer worms and Trojan horses. A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a file that appears harmless until executed.
Virus Origins
Computer viruses are called viruses because they share some of the traits of biological viruses. A computer virus passes from computer to computer like a biological virus passes from person to person.
Unlike a cell, a virus has no way to reproduce by itself. Instead, a biological virus must inject its DNA into a cell. The viral DNA then uses the cell’s existing machinery to reproduce itself. In some cases, the cell fills with new viral particles until it bursts, releasing the virus. In other cases, the new virus particles bud off the cell one at a time, and the cell remains alive.
A computer virus shares some of these traits. A computer virus must piggyback on top of some other program or document in order to launch. Once it is running, it can infect other programs or documents. Obviously, the analogy between computer and biological viruses stretches things a bit, but there are enough similarities that the name sticks.
Virus Protection
You can protect yourself against viruses with a few simple steps:
- If you are truly worried about traditional (as opposed to e-mail) viruses, you should be running a more secure operating system like UNIX. You never hear about viruses on these operating systems because the security features keep viruses (and unwanted human visitors) away from your hard disk.
- If you are using an unsecured operating system, then buying virus protection software is a nice safeguard.
- If you simply avoid programs from unknown sources (like the Internet), and instead stick with commercial software purchased on CDs, you eliminate almost all of the risk from traditional viruses.
- You should make sure that Macro Virus Protection is enabled in all Microsoft applications, and you should NEVER run macros in a document unless you know what they do. There is seldom a good reason to add macros to a document, so avoiding all macros is a great policy.
- You should never double-click on an e-mail attachment that contains an executable. Attachments that come in as Word files (.DOC), spreadsheets (.XLS), images (.GIF), etc., are data files and they can do no damage (noting the macro virus problem in Word and Excel documents mentioned above). However, some viruses can now come in through .JPG graphic file attachments. A file with an extension like EXE, COM or VBS is an executable, and an executable can do any sort of damage it wants. Once you run it, you have given it permission to do anything on your machine. The only defense is never to run executables that arrive via e-mail.
List of Anti Virus Programs
Norton/Symantec (Paid)
McAfee (Paid)
Trend Micro (Paid)
AVG (Free! + Paid)
AVAST (Free! + Paid)
MIT - Open Course Wave
Posted on January 10, 2008
Filed Under Civil Engineering, Computer (HW & SW), Downloads, Electrical Engineering, Knowledge Base, Mechanical Engineering, Petroleum / Environmental Engineering, Tutorials | Leave a Comment
I’m not sure if people know it or not but there is an Open Course Wave Website at MIT.
You can find tons of important stuff regarding most of engineering or any other field. If you are teaching, then the lectures can help you prepare lectures of world class quality. If you are studying it can broaden and can provide you in-depth knowledge of the subject.
You can also find tons of Video Lectures / Tutorials as well.
At the time of writing this blog the following list of course material can be found on their website:
Note: The list “only” contains “Electrical Engineering and Computer Science” “Undergraduate” courses.
A Sample lecture (Multipath, Arrays and frequency Reuse) is attached here: Sample lecture.
For a complete list of courses and downloads, please visit MIT OPEN COURSE WAVE.
- hope it helps 
Faraz Akhtar.
Electric Power
Posted on January 8, 2008
Filed Under Uncategorized | 1 Comment
“Electric power is the amount of work done by an electric current in a unit time.”
When a current flows in a circuit with resistance, it does work.
Devices can be made that convert this work into heat (electric heaters), light (light bulbs and neon lamps), or motion, i.e. kinetic energy (electric motors.
For more info consider Wikipedia.
Volt
Posted on January 8, 2008
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The volt (symbol: V) is the SI derived unit of electric potential difference. The number of volts is a measure of the strength of an electrical source in the sense of how much power is produced for a given current level.
For more info, consider Wikipedia.
How Lightning Works
Posted on January 6, 2008
Filed Under Energy, Tutorials | Leave a Comment
How lightning works?
clouds causes the charges to separate, there is a conductive path.
Lightning and atmospheric electricity
a historical essay on lightning research, access to data from the lighting teams, learn about LIS, OTD, LMS, an overview of field programs.
Museum of electricity - Lightning
what causes lightning?, what causes thunder?, the global electric circuit.
Lightning weather eye
what is lightning, introduction of lightning, experiment, safety, quiz.show how science relates to weather by using something as simple as static electricity.
Space Image
apolo 13 on it’s way to the moon, the final frontier, grand canyon, hurricane gladys from space, computer rendering of the international space station, MIR space station, pipe dark nebula.
Lightning Boy
a collection of the current and past advantures, freelance severse weather, storm, lightning
Lightning safety
free tutorial for lightning safety
Lightning Animation
http://www.chunder.com/ski/lightanim.html
Lightning Detector
what is lightning detector, lightning detectors vs. weather radar, aviation use., personal lightning detectors.
useful links
http://www.mos.org/sln/toe/lightning.html
http://www.peter-thomson.co.uk/tornado/Lightning.html
Manual, Electrical Books, Control System, Energy, Power Systems
Posted on January 6, 2008
Filed Under Downloads | 1 Comment
Manual of Engineering Drawing
http://mihd.net/ar726p
Electrical Books
http://rapidshare.com/files/28840859/Electrical_Books.rar
Problems and Solutions on Electromagnetism
http://rapidshare.com/files/1445185/Lim_Yung-Kuo.__ed.__Problems_and_Solutions_on_Electromagnetism__WS__2005__T__K__600dpi__679s__PG_.dj.html
Electric Power Systems
http://rapidshare.com/files/22509157/electric_power_systems.rar
CONTROL ENGINEERING
http://rapidshare.de/files/17236113/3935742010_Control_Engineering._A_guide_for_beginners_KINGDWARF.zip.html
Electric Power Generation, Transmission, and Distribution, (Electric Power Engineering Handbook)
http://w13.easy-share.com/2127051.html
Design Of Nonlinear Control Systems
http://depositfiles.com/files/1235369
The Engineering Handbook, Second Edition5
http://www.ftp2share.com/file/5208/the_engineering_handbook_0849315867.pdf.html
Design of Electrical Services for Buildings, 4th Edition
http://rapidshare.com/files/12679964/Design_of_Electrical_Services_for_Buildings.rar
Electrical Energy Systems
http://rapidshare.com/files/11930954/Electrical_Energy_Systems_0849321
Power Factor Correction
Posted on January 6, 2008
Filed Under Tutorials | Leave a Comment
What is power factor? the power factor is the cosine of the angle between the voltage
and current in the circuit or the ratio of the resistance to the impedance of the circuit and also the ratio of the real to the apparent power. To give more detail regarding power factor please follow the links below for additional information on power factor.
free pdf file for power factor - power in single phase ac circuits, complex power, the complex balance power, power factor correction.
free pdf file for power factor fundamental - power factor correction saves money, what is power factor, the power triangle, why do we install capacitors?, other benefits, summary of benefits for installing capacitor.
free pdf file for three phase theory - balanced load, three phase power, analysis of three phase balanced systems, single circuit of a three phase system, equivalent circuit for three phase balanced system, unbalanced three phase system, sysmetrical components,
graphical methord of solution, power associated with sequence components.
Useful Formulas for Power System Analysis & Power Factor Correction - formula symbols,free calculation for capacitors connected in parallel, capacitors connected in series, capacitive reactance, capacitance, capacitor kilovars, power factors, kilovars required to change power factor, equations for total power factor, total power, reactive power, voltage rise, released system capacity for power factor improvement, loss reduction for correction power factor, capacitor current, total power factor, quality factor, crest factor. note : just click the capacitor and input the value then automatically give you the answer.
power factor - power in resistive and reactive ac circuits, true power, reactive power, apparent power, calculating power factor, practical power factor correction.
free pdf file for power factor - the difference between volt amperes and watts, definition of a volt ampere reactive, a graphical representation of real, reactive, apparent and power factor.
FACTS ON POWER FACTOR
1. The reason why we need to improve power factor is to avoid poor voltage regulation.
2. Another reason is to decrease the reactive power.
3. On magnetizing component of a transformer the power factor is always leading.
4. On incandescent bulb or lamp the power factor is unity.
5. using synchronous motor can improve the power factor.
6. Using static capacitors can also improve the power factor and they are almost loss free.
7. If the system has poor power factor it will result to overloading of transformer as well as alternator.
8. For indicative circuit they can improve the power factor by connecting in series of capacitor.
9. KVAR are rated terms of the capacitors of power factor correction.
10. oN AC circuit which contain both resistor and conductor the power factor is leading between 0-1.
TYPES OF POWER FACTORS
1. unity power factor - equal real and apparent power.
2. leading power factor - when the current leads voltage by an angle and the true power will less than the apparent power.
3. lagging power factor - when the current lags voltage by an angle and the true power is less than the apparent power.
4. zero power factor - when there is phase difference of 90 degree between the current and the voltage. If the circuit has zero power factor you have no useful work to be done.
Energy?
Posted on January 6, 2008
Filed Under Tutorials | Leave a Comment
Type of energy
mechanical energy, kinetic energy, rotational energy, potential energy, units of energy, conservation forces and potential energy, conservation of energy for conservative forces, conservation of energy for non-conservative forces, conservation of energy problem solving.
What is energy?
joule, potential kinetic, efficiency, conduction, convection, radiation, power, watts, kilowatt-hour, energy sources, non-renewable, climate, change.
Energy library archives
http://www.rmi.org/sitepages/pid171.php
World of energy
safety fact sheet, energy fact sheet, electricity fact sheet, coal fact sheet, solar energy fact sheet, wind energy fact sheet, water energy fact sheet, geothermal fact sheet, thermal gradient energy fact sheet, biomass energy fact sheet, the greenhouse and you fact sheet, energy efficiency fact sheet, nuclear energy fact sheet, natural gas fact sheet, petroleum fact sheet, fuel cell fact sheet, solar hot water fact sheet, landfill gas fact sheet, remote power system fact sheet, oil refining fact sheet, gas to liquid fact sheet, scientist.
Energy
Enegy can be neither created nor destroyed, energy usually transferred, energ can be stored, a moving object has energy.
Useful links
http://www.eia.doe.gov/fueloverview.html
http://phun.physics.virginia.edu/topics/energy.html
http://www.energyquest.ca.gov/story/index.html
Polls
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