A PIR (Passive Infrared) sensor detects infrared light that is emitted from objects within its field of view. PIR sensors differ from other infrared sensors because they can only receive infrared waves. Because all objects emit infrared waves (electromagnetic waves that travel with heat), PIR sensors can detect objects that are in front of them. In fact, PIR sensors can detect many things that humans cannot. PIR sensors are used in many applications, such as night vision, motion detection, and laser range finding. How PIR Sensors Work PIR sensors are Read More

An air exchanger is a device that transfers stale air from inside a home to outside, and fresh air from outside to the inside. Air exchangers are often large and built directly into a home’s foundation in order to provide maximum fresh air levels at all times. This is important because indoor air is often five times more polluted than outside air, in both urban and rural areas. Also, energy is often wasted and heating/cooling costs high as doors and windows are often left open in order to freshen the Read More

Waste water can be treated in a variety of ways, depending on the facility’s abilities and the amount of waste that must be removed from it before it is released into the environment. Waste water generally passes through different treatment phases before it is released or reused. The process is carried out in a way that creates useful water options that can be recycled easier. The two main water options are gray water and black water. Gray water is derived from generally clean sources that do not contain human wastes Read More

Vulcanized rubber is a material that undergoes a chemical process known as vulcanization. This process involves mixing natural rubber with additives such as sulfur and other curatives. Vulcanization makes rubber much stronger, more flexible, and more resistant to heat and other environmental conditions. Vulcanized rubber makes both soft and hard objects, ranging from rubber bands to bowling balls. In fact, almost any rubber object consists of vulcanized rubber. How Vulcanized Rubber is Made It is necessary to use vulcanization to make commercial-grade rubber because natural rubber is not stable enough Read More

In the modern world, virtually everyone owns a microwave oven. How many people, though, stop to consider what exactly microwave ovens do or how they work? To anyone who has been alive over the past few decades, microwave ovens are as normal as anything else; to someone born even a century ago, however, they would be considered extremely futuristic. This article will explain what microwave ovens do and list the parts that make microwave ovens work so that readers can appreciate the science of these marvelous devices. What Do Microwave Read More

The word nanotechnology is a combination of the two terms "nano" and "technology." From this alone, it is apparent that nanotechnology is an application of scientific concepts at the level of molecules and particles, the sizes of which fall within the range of 1 to 100 nanometers. In a nutshell, nanotechnology refers to functional engineering at the level of molecules. Specifically, it is the deliberate application of production processes and technology at the molecular level in the order to achieve a desired result, to manufacture materials and consumables with unique Read More

The LRAD or the long range acoustic device that has been developed by American Technology Corporation is capable of emitting a maximum of 151Db sound within 30 degrees of where the device is pointing. This device can be used as a combatant deterrent weapon or crowd-control device by emitting sounds that are painful to the ears. The LRAD weighs about 210 kilograms and is capable of emitting sound within a 15 to 30 degree beam. The range of the LRAD is 300 to 500 meters and, at maximum volume, it Read More

In order to grow a bacterial culture in a lab, a growth medium has to be used to provide the right environment. Mannitol salt agar is a popular bacterial growth medium that biologists use to grow halphile bacteria (these grow fast in high salt concentrations) and can tell the difference between non-pathogenic and pathogenic Staphylococcus (ie parasitic to humans). Why Are Growth Media Important? Biologists use growth media in order to raise millions of bacteria in a colony. Some media are liquid – similar to a soup or broth, while Read More

Jets are able to move much faster than other types of aircraft and they especially move faster than regular forms of transportation such as trains and automobiles. In exchange for all the extra speed, however, jet engines must be designed and built differently than normal engines. This article will explain what jet engines do that are so special and list a number of parts that are crucial to the jet engine's ability to generate such high speeds. What Do Jet Engines Do Jet engines, also known as gas turbine engines, Read More

The majority of citizens in any well-established, first world country own at least one automobile. Few, however, stop to consider the amazing history of the automobile or how they work. Automobiles have thousands of pieces and parts that make everything from the headlights to the acceleration work. Likewise, the engine itself of any modern car can be enough to confuse the inexperienced. This article will explain what engines do and list some of the more basic parts of a car engine so that readers can clearly understand how engines work. Read More