Technology

Here is a list of arguably the most important ones. I will concentrate on inventions preceding the 1860's by only 200 years otherwise you would end up with a vast list encompassing all sorts of innovations.

• The steam engine. The variety that graced the Victorian era can be attributed to the work of Thomas Newcome and James watt. Most notably James Watt.
• The Railway. The first working line was laid down and opened between Manchester and Liverpool in 1832. Described as an invention to make the world smaller, it had many pioneers most notably George Stevenson and family.
• The Davy lamp. This invention protected miners from flammable gases that would have otherwise ignited in the presence of a naked flame. Its Inventor was Sir Humphry Davy.
• The Printing Press. Monumental in making ideas available to everyone, from newspapers to books. Prior to its invention all books were made by the arduous process of hand copying.
• Propeller driven ships. Isambard Kingdom Brunel demonstrated the supirior power of using propellers over conventional paddles during a race between two Royal Navy ships.
• The Sextant
• The Telescope
• Photography. This was just arriving by the 1860's.

It is important to take care of your laptop to keep it in good shape; prevention is always better than cure. There are a number of easy things that you can do to keep your laptop in great shape; following these easy steps will help to ensure that it lasts longer and will need less maintenance. As an added bonus, many of the steps will also maintain your laptop's speed.

(Battery is most common problem with any laptop, you need to remember do not over charge you laptop, leaving in power when battery is full, you could take out the battery when full charged and just plug the charger. (Most "New" even some of old ones still works when you just plug the power in with no battery) - ADDED

Possible the main point is take care of it as it is your 1000 million dollar suit case or your first born baby

Steps

1. Keep liquids away from your laptop. As tempting as it might be to drink coffee, soda, water or any other liquid near your laptop, accidents can happen all too easily. Spilled liquids may damage the internal components or cause electrical injury to the laptop. Short circuits can corrupt data or even permanently destroy parts. The solution is very simple: Keep your drinks away from your computer. Even if you're careful, someone else might bump into your desk or you. Or you can use a cup with a cover on it, so even if it does spill, the liquid doesn't go any where!

2. Having an available antivirus software would help. Even if you know what you download, it may contain a virus that can lead to a circuit error in your system hardware or slowness in the software.

3. Keep food away from your laptop. Don't eat over your laptop. The crumbs can go down between the keys in the keyboard and provide an invitation to small bugs. The crumbs can also irritate the circuitry. Worse, it makes the laptop look dirty if there are crumbs and food stains on it.

4. Always have clean hands when using your laptop. Clean hands make it easier to use your laptop touchpad and there will be less risk of leaving dirt and other stains on the computer. In addition, if you clean your hands before use, you will help reduce wear and tear on the coating of the laptop caused by contact with sweat and small particles that can act upon the laptop's exterior underneath your wrists and fingers.

5. Protect the LCD display monitor. When you shut your laptop, make sure there are no small items, such as a pencil or small ear-phones, on the keyboard. These can damage the display screen when shut; the screen will scratch if the item is rough. Close the lid gently and holding from the middle. Closing the lid using only one side causes pressure on that hinge, and over time can cause it to bend and snap.

6. Hold and lift the computer by its base, not by its LCD display (the screen). If you lift it by the screen part alone, you could damage the display or the hinges attaching it to the base. The display is also easily scratched or damaged by direct pressure - avoid placing pressure on it.

7. Don't pull on the power cord. Tugging your power cord out from the power socket rather than putting your hand directly on the plug in the socket and pulling can break off the plug or damage the power socket. Also, if you have the power point near your feet, avoid constantly bumping into the plug or you could loosen it and eventually break it.

8. Don't roll your chair over the computer cord. Stick the cord onto your desk with tape or a special computer cord tie which can be easily undone when you've finished using the laptop. Always try to keep most of the cord away from the floor or your legs; sometimes you can be so engrossed in what you're doing that you move your legs and forget the cord is there.

9. Plug in accessory devices into their proper slots. Always look at the symbols on the laptop carefully before inserting devices. Jamming a phone line into an Ethernet port or vice versa could damage the sockets, making it impossible to use them again. It is very important to observe this step.

10. Handle any removable drives with care. Floppy drives or CD drives that have been removed from your laptop can easily get crushed, dropped or pressed if you are careless. Put them straight into a bag or a storage box/case for safe keeping if you are not putting them back into the laptop.

11. Insert drives into their slots carefully and at the correct angle. Pushing the wrong drive into a socket, or at an angle, or even upside down can jam it.

12. Check to see if labels are affixed securely before inserting media into your laptop computer. Media such as CDs, DVDs or floppy disks should not have any loose label parts that might jam inside the laptop drive. Never insert undersized CDs, as these can damage the disk player permanently.

13. Don't expose your laptop to rapid temperature fluctuations. When bringing your laptop indoors during winter, don't turn it on immediately. Instead, let it warm to room temperature first. This will avoid any potential for damage to the disk drive from condensation forming inside the machine.

14. Don't leave your laptop in a car. Not only do the insides of cars experience large temperature swings that could damage a laptop, but a laptop (or laptop bag) is an inviting target for a smash and grab thief.

15. Have the unit cleaned once a year to remove internal dust. Get this done by a computer professional. If dust accumulates, the system cannot cool itself correctly. Heat can destroy the motherboard.

16. Use a properly-sized laptop case. Whatever you use to carry your laptop around in, be it a case, a bag or something you have made yourself, make sure that it it large enough to contain the laptop. This will avoid scratching, squeezing or even potentially dropping it.

17. Look into getting a laptop bag. Many breaks happen because of laptops being dropped or bumped. A bag greatly reduces the risk of damage.

18. Use and store in a well-circulated area. When you are using your laptop, do so in a place that has a constant air-circulation. Lots of people ruin their laptop by using it in an enclosed area and thus making the laptop overheat. It also helps if you store it in a well circulated area.

19. Use an old tooth brush to clean the area around the exhaust fan screen. If that gets plugged up, air flow is diminished and overheating can most certainly occur.

20. Try and keep the laptop on a flat surface. This prevents damage to the laptop. This step can be hard, particularly if you are going out with your laptop, but if there is a flat surface available to put your laptop on then do so.

21. Don't use your laptop on the bed. Repeated use of the laptop on the bed will cause the fans to suck up the dust and further debris which lies in the bed, ultimately blocking the fan. Refrain from this by using the laptop somewhere else than the bed.

Tips

Develop a preventive maintenance schedule to prevent problems rather than fixing them after they happen.

• Keep a record of your laptop computer details, such as serial number, make and model so that you can report theft or loss promptly.

• If you are working, you may have an opportunity to choose your laptop computer based on your requirements - for example, a sturdy model for rough use or a light one for frequent travel.

• You can make an easy screen protector from a thin piece of floppy foam cut the size of your screen. Place this between the base and top of your laptop each time that you turn off the laptop and close it. Do not leave it in there if the laptop is only sleeping or is not turned off. If the laptop overheats, this foam may cause the laptop to combust.
• You can make your own laptop case simply using items such as 2 pieces of cardboard joined together with strong tape and insert bubble wrap, or even a pillow slip, in between the cardboard. Make sure you get the measurements accurate! Or recycle an old bag - pad it well and size it down to fit your laptop securely.
• Look into laptop insurance. Look for sites on the internet but beware the "Zero excess" or "no excess" claim of a few.
• Put a label with your name, e-mail, cell phone number or other contact details on the laptop, the powercord and any other removable parts.
• Keep your laptop in a open area that has air circulation, when in use.
• Keep your laptop away from little kids ages 4 and under.
• Press the buttons softly so that they do not get peeled off.

Warnings

• Avoid putting your laptop on a carpet. The air vents on the back of the laptop help air to travel in and out. Anything which blocks the air vents is preventing hot air from escaping and only invites it back in again, which can result in overheating; leading to excessive lag and potential damage.
• Be aware of the "no excess" or "zero excess" of some laptop insurance companies; while it appears to be free of excess, you may have to pay again for the year in full to restart your insurance after a claim.
• Pets (like parrots that fixate on clicking, shiny objects) and children should be supervised when within a close proximity of your laptop.

The Radar that works on Doppler effect : it works on the principle of Doppler Effect. This effect is applicable to sound waves and electro-magnetic waves, which travel through some medium or through free space. The Doppler Effect states that when there is relative motion between the source of very high frequency signals and the observer, then frequency shift occurs.

In CW radar, a constant amplitude continuous microwave sine wave is transmitted. The echo is also a constant amplitude microwave sine wave of SAME frequency, but of lower amplitude, due to loss of energy during traveling of the wave.

While detecting the target like aeroplane, ship, missile etc. the echo undergoes change in its frequency. This change of frequency between the transmitted signal and received echo is used to determine the relative speed and direction of motion of the target. For this following formula is used -

V = 1.1 x fd x l

The above is true, but is also worth noting that Doppler radar offer's the forth degree of freedom in radar tracking as Range dot, or Doppler/Range-Rate. With more degrees of freedom then just Azimuth, Elevation & Range, tracking filtering can offer better results in say a Kalman Filter Tracking solution. Doppler profiles can be useful for distinction of distributions the difference between a man walking and a car driving etc (with man-portable radar like BLightER, or MSTAR). Doppler information can be used for SAR and ISAR imagery when the range Doppler matrix is collected at a high fidelity and interpolated correctly for a formation. It also should be noted that Doppler measurement is made via a Fourier transform rather then an statistical process, the statistical process relay own correlation of signal and de-correlation of noise where as the Fourier process is a reordering process and can provide a better signal to noise.