Robotic Lawn Mower

Brief Background:

The first Lawnmower was created in 1830 by putting a cloth trimming machine on wheels. However since then the Lawnmower has come a long way. Today many companies have produced fully automated robotic lawnmowers that can eliminate the need to ever go out and mow again. These mowers, much like robotic vacuums, allow people to not worry about these tedious tasks.

How It Works:

Robotic Lawnmowers are composed of three main systems: Navigation, Charging, and Cutting. The Navigation System uses a wire that the owner places around the edge of their yard and around places that should not be cut (ex. flowerbeds). The wires act as an invisible fence and allow the mower to map out the entire yard. The mower then plans a route to make sure that it cuts everything it needs to. The mower also has on board sensors that can detect if it were about to run into anything. The Charging System is comprised of a charging station located along the perimeter wire. When the mower gets low on battery it will follow the edge back to the station and charge itself until full where it then returns to the point it stopped. The Cutting System is set up so that the mower cuts more often but only a little length at each time. This allows for more nutrients to be but back into the lawn which in turn creates a better and healthier lawn.

Pros:

• Fully Automated
• Low maintenance

Cons:

• Expensive
• Will not create patterns
• Can only mow up to about one acre of lawn

Future:

In the future this technology will become even more widely used as it gets upgrades. Eventually they should be able to mow large spaces, have 100% coverage, and be able to make patterns.

Works Cited

Batya, et al. “How Do Robotic Lawn Mowers Work?” Robotic Lawn Mower Reviews UK & US, easylawnmowing.co.uk/how-do-robotic-lawn-mowers-work/.

“The History of Lawn Mowers.” Robomow, 3 Nov. 2016, www.robomow.com/en-GB/history-lawn-mowers/.

Railgun

Brief Background:

The idea of using electromagnetic force to propel projectiles has been around since WWI however the ideas were not tested until December 2010 when General Atomics tested their Blitzer electromagnetic railgun. This shot reached a speed over Mach 5 and exceeded a force of 33 megajoules. This force is roughly equal to a freight train traveling 100 mph. Now a shot can easily travel over 100 miles above Mach 7 with complete accuracy. It also has the power so travel through several layers of steel or concrete and deliver the same damage as a Tomahawk Missile.

How It Works:

Railguns are made of three basic components: two parallel rails, a projectile, and many capacitors. The projectile runs between the two rails and so that when a current is applied it travels up one rail, across the projectile, and then back down the other rail. Each rail creates a magnetic field but since they point in the same direction it creates an even stronger field that propels the projectile.

Pros:

• High speed
• Pinpoint accuracy
• Shoots farther than any other gun
• Does not take up much space on a ship
• Can penetrate through defenses
• Does not require guidence

Cons:

• Requires a large amount of energy
• Hard to transport
• Need to replace rails
• Magnetic Field can cause damage to nearby electronic equipment

Future:

In the future this weapon is expected to be able to reach speeds of Mach 10 and fire over 220 miles. It will also be able to shoot multiple rounds per minute. Scientists also expect that they could combine it with a typical combustion powder system to create an even better and more advanced version.

Works Cited

Allain, Rhett. “The Physics of the Railgun.” Wired, Conde Nast, 3 June 2017, www.wired.com/2014/08/the-physics-of-the-railgun/.

Dailymail.com, Mark Prigg For. “Radical Railgun Revealed: US Navy's 'Star Wars' Weapon That Can Fire Shells at Mach 6 and Penetrate Concrete 100 MILES Away Shown in Public for First Time.” Daily Mail Online, Associated Newspapers, 19 May 2015, www.dailymail.co.uk/sciencetech/article-2941525/Radical-railgun-fire-shells-mach-6-penetrate-concrete-100-MILES-away-shown-public-Navy.html.

Garrun, Daniel. “Highly Charged – the US Navy's Electromagnetic Railgun Programme.” Naval Technology, 27 Sept. 2012, www.naval-technology.com/features/featureus-navy-electromagnetic-railgun-programme/.

Danyang–Kunshan Grand Bridge

Brief Background:

The Danyang-Kunshan Grand Bridge is the worlds longest bridge stretching 164.8 km. The bridge has a span of 260 ft and is on average 100 ft above the ground. It was constructed for a high speed train connection between Shanghai and Nanjing. The bridge was opened in June 2011 after four years of work. Overall it took 10,000 people and $8.5 billion to build. Because of this bridge China now holds all top three spots for the worlds longest bridges.

How It Works:

The Danyang-Kunshan Grand Bridge is supported by over 9,500 concrete pillars. When constructing the bridge designers and engineers had to take into account the rivers, lakes, canals, deltas, lowland rice paddies, and uneven terrain. Also since the bridge is so immense they had to consider the curvature of the Earth. The main part of the bridge spans a 9 km section of the Yangcheng Lake. This section alone used 2,000 pillars and 450,000 tons of steel structure. This section was built to withstand magnitude eight earthquakes and collisions with naval ships that weigh up to 300,000 tons.

Pros:

• Provides quick transportation between Shanghai and Nanjing
• Breaks many different bridge records
• Provided many jobs

Cons:

• Expensive
• Time consuming

Future:

In the Future this bridge will be used as an outline to complete many other projects like it. China has already announced that they are planning to construct an even longer bridge or add onto the Danyang-Kunshan Grand Bridge to connect their entire country.

Works Cited

“Danyang–Kunshan Grand Bridge: The Longest In The World • Lazer Horse.” Lazer Horse, 25 Mar. 2018, www.lazerhorse.org/2014/05/24/danyang-kunshan-grand-bridge-longest-world/.

“The World's Longest Bridge - Danyang–Kunshan Grand Bridge.” Longest Bridge in the World - Danyang–Kunshan Grand Bridge - Facts and History, www.historyofbridges.com/famous-bridges/longest-bridge-in-the-world/.