Tuesday 28 September 2010

Bandung Air Show


~Semangat~
Semangat dalam perjuangan, tak sebatas tekad yang membakar, tapi semangat dalam perjuangan besertakan niat, do’a dan perbuatan

~Ilmu~
Ilmu itu bagaikan air yang tergenang kalau tidak di sampaikan, ilmu juga bagaikan air yang keruh kalau disampaikan tidak disertai pengamalan
Oleh: Mujahid Cinta







Saturday 25 September 2010

Electromechanics

In engineering, electromechanics combines electrical and mechanical processes. Mechanical engineering in this context refers to the larger discipline which includes chemical engineering, and other related disciplines. Electrical engineering in this context also encompasses software engineering, computer engineering, and other related fields. This refers to the three major engineering disciplines of electrical engineering, mechanical engineering and civil engineering under which all other engineering disciplines are classified.

Devices which carry out electrical operations by using moving parts are known as electromechanical. Strictly speaking, a manually operated switch is an electromechanical component, but the term is usually understood to refer to devices such as relays, which allow a voltage or current to control other, isolated voltages and currents by mechanically switching sets of contacts, solenoids, by which a voltage can actuate a moving linkage, vibrators, which convert DC to AC with vibrating sets of contacts, etc. Before the development of modern electronics, electromechanical devices were widely used in complex circuits, including electric typewriters and teletypes, and up to the complexity of an electromechanical digital computer.

Wednesday 22 September 2010

Adjustable Capacitor with Dielectric

MIT Physics Demo

First, an adjustable parallel-plate capacitor is held at a constant voltage. As the separation between the plates is widened, the electrometer shows charge (or current) flowing off of the plates, while the electroscope shows no change in voltage. 

Notice (by the deflection of the needle) that more charge flows off of the plates when they are closer together, and less when further apart. When the plates are brought back together, we see charge flowing back onto of the plates. Next, we deposit a fixed amount of charge onto the left plate. 

Now, when the separation is widened, the electroscope shows a rising voltage, even as the amount of charge stays constant. When a block of plexiglass (a dielectric) is inserted between the plates, the voltage drops. However, when the plexi is removed, the voltage rises back up again, showing that the charge is still there. This is one of the main reasons capacitors are built with dielectrics between their plates, more charge can be stored at a lower voltage.



Source: MIT Department of Physics

Saturday 18 September 2010

Pameran Kedirgantaraan

Disusun Ulang Oleh:

Arip Nurahman
Department of Physics
Faculty of Sciences and Mathematics, Indonesia University of Education

and

Follower Open Course Ware at Massachusetts Institute of Technology
Cambridge, USA

Department of Physics
http://web.mit.edu/physics/
http://ocw.mit.edu/OcwWeb/Physics/index.htm

&

Aeronautics and Astronautics Engineering
http://web.mit.edu/aeroastro/www/
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/index.htm















 
Pameran kedirgantaraan atau pameran penerbangan (Inggris: airshow) adalah pameran yang umumnya diikuti oleh pabrikan atau kontraktor yang bergelut dibidang kedirgantaraan. Umumnya yang dipamerkan berupa pesawat terbang komersial, pesawat tempur dan teknologi pendukung seperti radar, rudal, sistem navigasi bahkan hingga ban atau roda pesawat.

Sejarah

 

 

Pameran kedirgantaraan Perancis

 

 

Sejak ditemukannya pesawat terbang yang diyakini sebagian besar kalangan oleh Wright Bersaudara (Wilbur Wright dan Orville Wright) pada Desember 1903, sampai enam tahun sesudahnya, khususnya di Eropa, belum ada pameran kedirgantaraan atau yang umum dikenal sebagai pameran penerbangan (Air Show). Dorongan untuk memamerkan kemajuan dibidang kedirgantaraan muncul ketika Wright Bersaudara melakukan kunjungan ke Perancis pada ahun 1908.


Pada waktu itu, Perancis sudah menjadi pusat kegiatan penerbangan Eropa hingga banyak acara yang berhubungan dengan kegiatan penerbangan berlangsung disana, termasuk sebuah pertemuan yang berlangsung di Port Aviation di Juvisy di luar kota Paris 23 Mei 1909.

Tak lama setelah itu, tepatnya pada tanggal 25 Juli 1909 Louis Bleriot terbang melintasi selat Inggris dengan pesawat sayap tunggal (monoplane) hasil rancangannya sendiri. Guna merayakan keberhasilannya, diadakan sebuah perayaan satu pekan kedirgantaraan yang meriah dengan nama Grande Semain d'Aviation de la Champagne yang berlangsung di Rheims antara 22 hingga 29 Agustus. Acara ini kemudian diikuti dengan sebuah pameran udara Internasional di Grand Palais di Champs Elysees dari tanggal 3 hingga 17 Oktober 1909 dengan demonstrasi terbang yang diadakan di Juvisy. Acara inilah yang merupakan asal muasal Pameran kedirgantaraan Paris-Le Bourget yang nama resminya adalah Le Salon International de l'Aeronatique et del'Espace de Paris-Le Bourget.

Pameran kedirgantaraan Inggris

 

 

Inggris kemudian mengikut jejak Perancis dalam urusan pameran kedirgantaraan dengan menyelenggarakan demonstrasi terbang di Doncaster dan Blackpool pada 15 Oktober 1909.

Di Inggris, perkembangan pameran kedirgantaraan kemudian tidak terlepas dari peranan Himpunan Perusahaan Kedirgantaraan Inggris (SBAC, The Society of British Aerospace Companies) yang sebelumnya bernama The Society of British Aircraft Constructors yang mengorganisir pameran pesawat sejak 1918.

Pameran pesawat utama di Inggris mula-mula dilaksanakan di Olympia, London tetapi sejak 1932 dipindahkan ke lapangan udara sehingga dapat dimasukkan acara demonstrasi terbang. Inggris kemudian membangun lapangan udara Hampshire pada tahun 1948 di sebuah wilayah bernama Farnborough yang kemudian terkenal sebagai tempat pameran pameran kedirgantaraan termasuk pesawat, perlengkapan dan perkembangan teknologinya. Sampai tahun 1962 pameran kedirgantaraan Perancis diselenggarakan setiap tahun sekali, dan sesudah itu setiap dua tahun sekali dalam bulan yang sama yakni september.


Perkembangan pameran kedirgantaraan

 

 


Selain Inggris dan Perancis, perkembangan teknologi kedirgantaraan juga berkembang di berbagai kawasan khususnya Timur tengah dan Asia Pasifik. Seiring dengan berkembangnya transportasi udara dan kebutuhan kebutuhannya, juga tidak terlepas dari kebutuhan untuk memodernisasi peralatan pertahanan udara di kawasan tersebut. Umumnya, pameran kedirgantaraan tidak terlepas dari pameran teknologi pertahanan khususnya teknologi pertahanan udara seperti pesawat tempur, radar dan rudal. Terlepas dari tersimpannya konflik antar negara maupun kebutuhan memodernisir peralatan pertahanan suatu negara.



Di kawasan Asia Pasifik, dikenal pameran kedirgantaraan Asian Aerospace yang diselenggarakan di Singapura yang dimulai pada 1981, kemudian pameran kedirgantaraan di Korea, Jepang, dan Tiongkok yang dikombinasikan dengan pameran pertahanan untuk angkatan darat dan angkatan laut, Pameran Lima (kombinasi antara udara dan laut) di Malaysia tepatnya di Langkawi, pameran pertahanan Asia di Thailand dan untuk Indonesia pada masa sebelum dilanda ekonomi ada pameran yang dikenal sebagai Indonesian Air Show (1986 dan 1996). Untuk kawasan timur tengah terdapat pameran kedirgantaraan dan pertahanan Dubai.



Diluar kawasan itu, terdapat pameran kedirgantaraan Moskwa (MosAero) di Moskwa, Rusia, Pameran kedirgantaraan Oshkosh di Amerika Serikat dan pameran Avalon di Australia.


Di dalam pameran kedirgantaraan umumnya terjadi transaksi atau kontrak atara pabrikan atau perusahaan pembuat pesawat terbang, kontraktor dirgantara yang berperan dalam pemeliharaan sampai perlengkapannya baik perlengkapan yang bersifat teknis sampai bersifat kenyamanan, baik sipil maupun militer. Meski kontrak tersebut tidak langsung timbul dalam penyelenggaraan pameran. Melalui pameran tersebut kalangan industri dapat berinteraksi, mengetahi informasi dari pesaing maupun untuk komersial. Sementara bagi pengamat kedirgantaraan, dapat mencatat berbagai kemajuan yang sudah diperoleh.

Untuk transaksi, dicatat terjadi transaksi besar besaran selama pameran seperti transaksi untuk penjualan pesawat F-16 terbesar untuk memenuhi kebutuhan pertahanan NATO setelah mengalahkan Mirage F-1 dari Perancis setelah diadakan uji terbang, kontrak penjualan pesawat Boeing 777 kepada Singapore Airlines yang tercatat memesan 77 buah pesawat dan kontrak penjualan Airbus A 380 ke berbagai maskapai penerbangan pada awal abad ke 21.


Sejumlah atraksi kedirgantaraan juga mewarnai pameran kedirgantaraan, yang umumnya secara tidak langsung dikaitkan dengan penawaran pesawat khususnya pesawat tempur yang dipromosikan, seperti atraksi team Red Arrows Angkatan Udara Inggris yang dapat dikaitkan dengan promosi penjualan pesawat latih Hawk, team Ruskiye Vitayasi (Ksatria Rusia) dengan Su-27 Flanker, Stirji (Rusia) dengan MiG 29 maupun Thunderbirds dengan F-16. Atrasksi lain adalah atraksi tunggal untuk menunjukkan kemampuan manuver pesawat pesawat yang ditawarkan seperti Atraksi Su-37 Flanker dari Rusia yang mampu melakukan manuver yang belum dapat dilakukan pesawat tempur satu generasi dari Barat dengan manuver kompleks seperti Kobra Pugachev, Bell dan Kulbit.

Namun kecelakaan sering terjadi dalam atraksi-atraksi udara ini. Diantaranya gagalnya Manuver MiG 29 Fulchrum yang mengakibatkan pesawatnya menukik tak terkendali, patah dan terbakar di udara pada pameran Paris-Le Bourget 1989, yang beruntung pilotnya dapat selamat dengan kursi lontar dari ketinggian 30 meter. Meski dianggap sebuah kegagalan, namun biro MiG yang memproduksi MiG 29 secara tidak langsung dapat mempromosikan bahwa kursi lontar Zvesda yang ternyata sangat tanggap. Hal yang sama terjadi saat Tu-144 Concordski terbang tidak terkontrol dan jatuh saat pameran Paris-Le Bourget 1973.


Selain itu, pesawat teknologi tinggi yang ikut dipamerkan sering menjadi pesawat yang tidak begitu laris dipasaran internasional. Karena umumnya, pemakai pesawat tidak hanya melihat dari segi teknologinya, melainkan juga mempertimbangkan hal hal lain seperti bagaimana pengguna pesawat lain dalam menggunakan produk tersebut baik kehandalan sampai masalah perawatan dan suku cadang.

Wikipedia


Tuesday 14 September 2010

Rocket Races

Audience: Educators
Grades: 3-12


Students construct balloon-powered racing cars using a foam tray and drinking straws. They then test the cars along a measured track on the floor. At the conclusion of the activity, students submit a detailed report on their racer design and how it performed in the trials.

Rocket Races   [936KB PDF file]

This lesson plan is part of the Rockets Educator Guide.

Friday 10 September 2010

Air Show

An air show is an event at which aviators display their flying skills and the capabilities of their aircraft to spectators in aerobatics. Air shows without aerobatic displays, having only aircraft displayed parked on the ground, are called "static air shows".



Outline

 

 



A month after Blériot's crossing of the English Channel the aviation week in Reims, France, August 1909, caught special worldwide attention.


Some air shows are held as a business venture or as a trade event where aircraft, avionics and other services are promoted to potential customers. Many air shows are held in support of local, national or military charities. Military air firms often organise air shows at military airfields as a public relations exercise to thank the local community, promote military careers and raise the profile of the military.






Aviation Nation 2006 at Nellis Air Force Base, United States



Air show "seasons" vary around the world. Whereas the United States enjoys a long season that generally runs from March to November, other areas often have much shorter seasons. The European season usually starts in late April or Early May and is usually over by mid October. The Middle East, Australia and New Zealand hold their events between January and March. However, for many acts the "off season" does not mean a period of inactivity, they use time for maintenance and practice.






The Patrouille Suisse performing at the ILA Berlin Air Show




The type of displays seen at an event are constrained by a number of factors, including the weather and visibility. Most aviation authorities now publish rules and guidance on minimum display heights and criteria for differing conditions. In addition to the weather, pilots and organizers must also consider local airspace restrictions. Most exhibitors will plan "full," "rolling" and "flat" display for varying weather and airspace conditions.




The types of shows vary greatly. Some are large scale military events with large flying displays and ground exhibitions while others held at small local airstrips can often feature just one or two hours of flying with just a few stalls on the ground. Air Displays can be held during day or night with the latter becoming increasingly popular. Shows don't always take place over airfields; some have been held over the grounds of stately homes or castles and over the sea at coastal resorts.



Attractions

 

 



Air racing at an air show in England: the Red Bull Air Race heat held at Kemble Airfield, Gloucestershire. The aircraft fly singly, and pass between pairs of pylons

Before the Second World War, air shows were associated with long distance air races, often lasting many days and covering thousands of miles. While the Reno Air Races keep this tradition alive, most air shows today primarily feature a series of aerial demos of short duration.

Most air shows will feature warbirds, aerobatics, and demonstrations of modern military aircraft, and many air shows offer a variety of other aeronautical attractions as well, such as wing-walking, radio-controlled aircraft, water/slurry drops from firefighting aircraft, simulated helicopter rescues and sky diving.

Specialist aerobatic aircraft have powerful piston engines, light weight and big control surfaces, making them capable of very high roll rates and accelerations. A skilled pilot will be able to climb vertically, perform very tight turns, tumble his aircraft end-over-end and perform manoeuvres during loops.



Solo military jet demos, also known as tactical demo, feature one aircraft, usually a strike fighter or an advanced trainer. The demonstration focuses on the capabilities of modern aircraft used in combat operations. The display will usually demonstrate the aircraft's very short (and often very loud) takeoff rolls, fast speeds, slow approach speeds, as well as their ability to quickly make tight turns, to climb quickly, and their ability to be precisely controlled at a large range of speeds.

Manoeuvres include aileron rolls, barrel rolls, hesitation rolls, Cuban-8s, tight turns, high-alpha flight, a high-speed pass, double Immelmans, and touch-and-gos. Tactical demos may include simulated bomb drops, sometimes with pyrotechnics on the ground for effect. Aircraft with special characteristics that give them unique capabilities will often display those in their demos; For example, Russian fighters with Thrust vectoring may be used to perform Pugachev's Cobra or the Kulbit, among other difficult manoeuvers that cannot be performed by other aircraft. Similarly, an F-22 pilot may hover his jet in the air with the nose pointed straight up, a Harrier or Osprey pilot may perform a vertical landing or vertical takeoff, and so on.

See also

 

 

Wikipedia

Sunday 5 September 2010

Fusion Power

Fusion power is the power generated by nuclear fusion processes. In fusion reactions two light atomic nuclei fuse together to form a heavier nucleus (in contrast with fission power). In doing so they release a comparatively large amount of energy arising from the binding energy due to the strong nuclear force which is manifested as an increase in temperature of the reactants. Fusion power is a primary area of research in plasma physics.

The term is commonly used to refer to potential commercial production of net usable power from a fusion source, similar to the usage of the term "steam power." The leading designs for controlled fusion research use magnetic (tokamak design) or inertial (laser) confinement of a plasma, with heat from the fusion reactions used to operate a steam turbine which in turn drives electrical generators, similar to the process used in fossil fuel and nuclear fission power stations.

As of July 2010, the largest experiment by means of magnetic confinement has been the Joint European Torus (JET). In 1997, JET produced a peak of 16.1 megawatts (21,600 hp) of fusion power (65% of input power), with fusion power of over 10 MW (13,000 hp) sustained for over 0.5 sec. Its successor, the International Thermonuclear Experimental Reactor (ITER), was officially announced as part of a seven-party consortium (six countries and the EU). ITER is designed to produce ten times more fusion power than the power put into the plasma. ITER is currently under construction in Cadarache, France.

Inertial (laser) confinement, which was for a time seen as more difficult or infeasible, has generally seen less development effort than magnetic approaches. However, this approach made a comeback following further innovations, and is being developed at both the United States National Ignition Facility, the French Laser MĂ©gajoule as well as the planned European Union High Power laser Energy Research (HiPER) facility. NIF reached initial operational status in 2010 and has been in the process of increasing the power and energy of its "shots". Fusion ignition tests are to follow.

Fusion powered electricity generation was initially believed to be readily achievable, as fission power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production was still believed to be unlikely before 2050.

Wednesday 1 September 2010

Solid-state physics

Solid-state physics is the study of rigid matter, or solids, through methods such as quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from their atomic-scale properties. Thus, solid-state physics forms the theoretical basis of materials science. It also has direct applications, for example in the technology of transistors and semiconductors.