Musculoskeletal, nervous, respiratory, and circulatory systems in Essay

Musculoskeletal, nervous, respiratory, and circulatory systems in ergonomics - Essay Example The human skeleton has 206 bones. The bones’ mobility is dependent on muscle contraction. Every muscle is attached by a connective tissue to two or more bones. First, the spine enables bending, twisting, and holding the body in an upright position, along with providing an avenue through the spinal cord for the brain to communicate with the whole body. Fixed postures and prolonged seating causes low back pain. This is as a result of a shift in position of the spine discs. Second, muscles contain thousands of tiny aligned fibers. Muscles are responsible for the movement in the human body. Muscles function to produce motion and force. It generates force by contraction. Muscles use a lot of nutrients and oxygen. The muscle activity results in the production of metabolic wastes, such as, lactic acid and CO2. In this perspective, prolonged muscle contraction increases muscle fatigue and risk of injury (Kahn & Line, 2008). Third, tendons are tough and flexible band of fibrous connective tissue which joins muscles to bones. They transfer forces and movements from the muscles. Most of them run through guiding sheaths and do not stretch. Tendinitis is an inflammation of the tendon that causes point swelling. Next, ligaments are groups of dense, white, fibrous elastic tissue. A ligament connects bones to bones in order to form a joint. Majority of the ligaments limit dislocation. They stabilize and support the joints by holding the joints together. A sprain causes the fibrous elastic tissues to stretch or get torn from the bone (Pheasant & Haslegrave, 2011). Fifth, fascia is a thin, gelatinous membrane that surrounds and is fused with the blood vessels, muscles, bones, tendons, nerves, and organs throughout your body. It supports, connects, and compartmentalizes various body parts. Strain stretches the fascia leading to pain. Lastly, bursa is fluid-filled sac located at bone joints and it is lined with a synovial membrane. It

Different De-Icing Systems for Aircraft Research Paper

Different De-Icing Systems for Aircraft - Research Paper Example This paper looks at the various systems used for de-icing in airplanes. The protection of engines and the aircrafts can take fundamental forms. One of them is the removal of ice once it has been formed, or probes be used to prevent it from forming. De-icing is the removal of ice, snow, or hoarfrost on the surface of the airplanes. However, deicing is correlated with anti-icing, which is defined as the use chemicals in the surfaces of the aircraft. The chemicals do not only de-ice but also stay put on a surface and prevent buildup of ice for a period, or hinder adhesion of ice to make mechanical removal easier. Therefore anti-icing is also a form of de-icing (Skybrary, 2012). Removing ice on the surface of the aero planes takes various forms. It can be done using chemical methods such as scrapping and pushing. In order to achieve this, heat must be applied on the surface of the plane, by using liquid or dry chemicals that are formed to decrease the freezing point of water. Such chemic als include alcohols, brines, salts, and glycols. Moreover, they can combine many of these chemicals in order to enhance their effectiveness. De-icing can also be done through the use of a protective layers such as the use of viscous liquid known as the anti-icing fluid on the surface of the aero plane to absorb the contaminate. ... In addition, it dilutes the anti-icing fluids used thus changing into a contaminant itself (Lankford, 1999). Salt has also been another method that is used to de-ice. It has traditionally been used to de-ice roads with the addition of sand and gravel. This has been effective due to the availability of the chemical sodium chloride also known as rock salt. This method is effective and inexpensive to use. Moreover, it is readily available. However, this method cannot be used for temperatures below -18 degrees centigrade, which mostly is easily achieved by highflying aeroplanes. Moreover, this method causes corrosion on the surface of the aeroplane, therefore rusting the steel, which is one of the materials used to make the surface of the aeroplanes (Roskam, 2000). In addition, de-icing on the aeroplanes uses another method that uses different categories of salts such as calcium chloride and magnesium chloride. These salts are important since they condense and depress the freezing point of water to a lower temperature. However, this salt also causes exothermic reaction. In the recent years, more advanced salts have been developed which do not cause environmental issues that was previously affected by the salts. They also have a longer residue effect when used together with the traditional salts such as salt brines and solids (Roskam, 2000). In addition, de-icing has taken various forms with the development of technology. More recently, the flight industry has turned into using the infrared de-icing system. This method is advantageous in that it is subsequently faster than the traditional salt systems and conservative heat transfer modes used by