Know the superconducting material

A. History and Background 

The first superconductor was discovered by a Dutch physicist, and his name Heike Kamerlingh Onnes, who is a researcher at Leiden University in 1911. On July 10, 1908, Onnes succeeded in liquefying helium by cooling elements up to 4 Kelvin or -269 Celsius. Then in 1911, Onnes began to study the electrical properties of metals at very cold temperatures, probably due to the hypothesis that high rates of movement of electrons in the phonon. At the time it was known that the resistance of a metal will come down when cooled below room temperature, but no one can know how the lower limit of resistance is achieved when the metal temperature approaches 0 K or absolute zero.

 
Some expert scientists at that time as William Kelvin predicted that electrons flowing in the conductor will stop when the temperature reaches absolute zero. On the other hand, other scientists, including Onnes estimated that the barriers will disappear in these circumstances. To find out the truth, Onnes then drain current in a very pure mercury wire and then measure the resistance while lowering the temperature. At a temperature of 4.2 K, Onnes was surprised to find that its resistance suddenly disappeared. Current flows through the wire mercury constantly.

superconductors made ​​with the aim to obtain the energy efficiency of each machine that has been made ​​before, it is of course very beneficial in helping every human activities. Imagine if a superconductor can be created and used in the quality of your internet or telephone network, you will get good again without costing so much. Now it's like super-fast trains have used the principle of the superconductor has zero resistance.

B. Defenition

Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain material when cooled below a characteristic critical temperature. which means there is no resistance when the electrons moving from one point to the another point.

Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of perfect conductivity in classical physics. (http://en.wikipedia.org/wiki/Superconductivity)

Refractometer Abbe

In physics, we certainly know who called with the fluid. Fluids affect the movements of particles and scale objects around the fluid. Suppose a fluid liquid, say fluid example is a cup of water that we do not yet know the content in detail both chemically and in the general. In the physical sciences we are able to analyze the water content by using several methods just call it like X-Ray Diffraction or with a refractometer.

 
Refractometer is itself a tool used to determine and analyze the content or concentration of the dissolved material. This means that we are not only able to find the solution in terms of content but we are also able to calculate how much the concentration of dissolved material in a liquid. The principle of the work done by refraktomere is based on the principle of the properties of light, ie, reflection, refraction, and even diffraction.

For additional information, tools refractometer which is known by many people, known as Abbe refractometer, which is an instrument invented by Dr.. Ernst Abbe, a physicist who originated from Germany and was discovered in the early 20th century BC. Abbe took the principle of interference of a light which strike two transparent materials.

 
In order to more easily, here is the following explanation of the refractometer According to Wikipedia.org

Ernst Abbe (1840–1905), working for the Zeiss Company in Jena, Germany in the late 19th century, was the first to develop a laboratory refractometer. These first instruments had built-in thermometers and required circulating water to control instrument and fluid temperatures. They also had adjustments for eliminating the effects of dispersion and analog scales from which the readings were taken.

In the Abbe' refractometer the liquid sample is sandwiched into a thin layer between an illuminating prism and a refracting prism. The refracting prism is made of a glass with a high refractive index (e.g., 1.75) and the refractometer is designed to be used with samples having a refractive index smaller than that of the refracting prism. A light source is projected through the illuminating prism, the bottom surface of which is ground (i.e., roughened like a ground-glass joint), so each point on this surface can be thought of as generating light rays traveling in all directions. A detector placed on the back side of the refracting prism would show a light and a dark region.

Over a century after Abbe's work, the usefulness and precision of refractometers has improved, although their principle of operation has changed very little. They are also possibly the easiest device to use for measuring the refractive index of solid samples, such as glass, plastic, and polymer films. Some modern Abbe refractometers use a digital display for measurement, eliminating the need for discerning between small graduations. However, the user still has to adjust the view to get a final reading.

The first truly digital laboratory refractometers began appearing in the late 1970s and early 1980s, and no longer depended on the user's eye to determine the reading. They still required the use of circulating water baths to control instrument and fluid temperature. They did, however, have the ability to electronically compensate for the temperature differences of many fluids where there is a known concentration-to-refractive-index conversion. Most digital laboratory refractometers, while much more accurate and versatile than their analog Abbe counterparts, are incapable of readings on solid samples.

In the late 1990s, Abbe refractometers became available with the capability of measurements at wavelengths other than the standard 589 nanometers. These instruments use special filters to reach the desired wavelength, and can extend measurements well into the near infrared (though a special viewer is required to see the infrared rays). Multi-wavelength Abbe refractometers can be used to easily determine a sample's Abbe numbers.

The uniqueness and beauty of the Sea Worm

Previously I apologize because it was so long ago does not make the article into this blog. That is because the persistence of the busy-busy I had to do on campus (students are still advised). Okay, do not linger.

Well, this time we will discuss is called a worm. Eitss, patient first, because this time we are not talking about worms in your mind. Maybe, when you see the title of my article this time, you will immediately think with worms that its disgusting have colors that make your eyes closed because of disgust and even seemed ludicrous. However, worms are we going this time peel (Peel continues as the worm hulled) no earthworms and friends. Rather we will discuss worms residing in the ocean. Which according to people is one of the animals in the aquarium decoration. And in fact, be a high protein source for among certain people.

Okay, Let's kick ass one by one.

Worms, worms What exactly is it? The worm is no vertebrate animal that has a long flat shape and there is even a hairy and some are not hairy. The worms are even some that are beracung some are not toxic. In general, the worms can be found in areas that have water situation is not too much or in damp places. It is in because of the worms mostly by using body surface. Therefore, we often find worms in the soil a dirty, damp and even rot.

Because we are considering the class of worms rather than dirty, then we will immediately jump worm that frequent bathing class alias net. One is a marine worm. In other types of marine worms, animals in the biological sciences we often hear the term marine worm called with a class of Polychaeta. Basically the meaning of Polychaeta have had lots of hair (remember not the fur, because fur is much different from the same hair) According to Wikipedia,

Polychaeta are a class of annelid worms which generally live in the sea. The entire body surface polychaeta contain stiff hairs or setae which coated cuticle so slippery and stiff. His body was attractive color, such as reddish purple. Each segment is equipped with a pair polychaeta body motion of the tool or tools swim called parapodia. This tool also acts as a respirator. Most of the measuring 5-10 cm, but there are less than 1 mm and some are up to 3 m.

Happy Idul Fitri, 1 Syawal 1432 H

Thursday, 30th August 2011 I as a moslem gain a great great victory after pretend my thirsty and my hunger for a month. (ah susah kali pun pake bahasa Inggris, sekali-kali pake Bahasa aja lah, izin yo Om Google)

Haduh, hari ne ane di Sibolga merayakan yang namanya lebaran, berangkat tanggal 29 Agustus kemarin pas selesai subuh, dan berharap yang namanya idul fitri 1 syawal 1432 H itu jatuh pada keesokan harinya.....

Tapi........
Setelah mengalami perjalanan selama 10 jam (kurang lebih) dan telah menempuh jarak sejauh 300 Km mungkin ditambah dengan rintangan yang mampu membuat jantung anda berdetak kencang, ternyata harapan yang ditunggu-tunggu untuk menikmati lebaran di kota sibolga tidak seperti yang diinginkan. Dasar, 1 syawal 1432 H ditetapkan pada lusa harinya yang bertepatan pada 31 Agustus 1432 H.

Indonesia, selalu bermasalah dengan yang namanya penetapan 1 syawal... dan banyak yang membuat hal ini menjadi suatu perbedaan yang signifikan..
salah satu ane baca di situs favorit indonesia, yakni kaskus.us ada komen yang mengatakan bahwa perbedaan waktu masing-masing negara di dunia sampai yang paling jauh itu tidak lebih dari 24 jam, namun perbedaan lebaran malahan lebih dari 24 jam, hal itu tentu membuat kita gerah, karena memang perbedaan waktu yang nyata/ real itu tidak pernah lebih dari 24 jam sehingga apabila di belahan bumi yang lain sudah melihat hilal maka kita juga sudah masuk yang namanya bulan baru karena ingat bulan mengitari bumi.

Akhirnya ane liat situs di moongiant.com, dan ternyata pada tanggal 29 Agustus pukul 5 sore kemarin bulan sudah memasuki bulan baru???? waduh, bener juga ya dan ternyata di daerah cakung, Jakarta Timur telah terlihat hilal diatas 3,5 derajat???

Dilema bagi saya...
Secara determinasi science, hilal sudah nampak dan itu sudah hukum alam bahwa yang namanya perubahan fase bulan merupakan waktu yang periodik dan tersusun secara sistematis.... dan memang menurut informasi yang benar, ramadhan berusia 29,5 hari..

Mana yang benar????

namun, saya akui, saya berlebaran pada hari selasa 30 Agustus 2011... apabila ada yang berhari raya pada tanggal 31 Agustus 2011 itu pun tidak masalah bagi saya, sebagai umat islam tentu yang namanya perbedaan jangan di jadikan sebagai sebuah permusuhan, karena Kebenaran Mutlak dari Allah SWT....

Last but not least
Finally, Allahumma firlil muslimina wal muslimat fil ahya min hum wal Amwat
Allahuakbar Allahuakbar Wallillahihilhamd

Mohon Maaf Lahir dan Bathin, Minal Aidzin wal Faizin, Selamat Hari Raya Idul Fitri 1 Syawal 1432 Hijriyah

Ultra Short Focal Projector NEC, solution presentations in small rooms

The presentation was not confined to the office. Today, the world of education became more familiar with the activities of this one. The problem, to make a presentation, it takes a large room so that the projector can project images with an ideal distance. While the average classroom sizes are small. 

Similar problems were often encountered in a small office space. Finally, many companies are forced to use only a large room for meetings. The problem, when a large meeting room was full of small meeting rooms, had to be used even if can not use the projector. 

Spacious room is often a problem when using a projector. However, the problem is now resolved with the presence of the latest generation of Ultra Short Focal Projector NEC. By announcing the latest generation of Ultra-Short Projectors are available in four types U300X, U250X, U310W, and U260W this can indeed be a solution presentations in small rooms. 

Eliminating shadows and glare that normally found with standard projection systems, can be achieved by mounting the projector to the wall above the screen. This makes the Ultra Short Focal projector ideal for education environments using standard or interactive whiteboard. With a very short projection distance, the reflection method, and the distance is unbelievably close to the cabinet, making use of this model is very efficient room. 

In fact, this projector can be used up to the smallest distance of about 47.5 centimeters to produce the display by 63 inches. As a comparison, conventional projectors usually takes a distance of about 1.2 meters to produce a display of about 60 inches. All that can happen thanks to the Mirror Aspheric Technology, the technology that reflects the light through the glass. 

For information, the projector can be used on a table, sideboard, or mobile trolley has a 3D-readyU series created by Link and DLP DLP technology from Texas Instruments. It is as future-proof next-generation projectors. 

For corporate customers who do not have the space needed for a standard projector, this projector offers an attractive alternative. They offer XGA and WXGA resolution, respectively, and up to 3100 ANSI lumens brightness. Their connectivity including dual HDMI inputs and a computer, and variable audio out to connect the projector to external speakers and volume control via remote control the projector. 

The question is, with such a close distance, what about the quality of the resulting appearance? NEC Projectors NEC Display Solution manufactured by Japan which is one of the leading companies in the world's projector market. 

NEC Display images through the projector will be very bright because it has a brightness level of the calculation of light projected onto the screen quite large with a 2000:1 contrast ratio. 

Another plus, this projector has a much more concise models and futuristic than with previous generations. For use in the classroom, NEC projectors can help the learning process more exciting and enjoyable place. 

Pupils would prefer to learn through visualization, compared to only learn by listening to the teaching method. Therefore, the use of the projector probably has become an absolute necessity in every classroom. Moreover, if the projector is already 3D-Ready technology like that of NEC projectors of this type. 

Besides suitable for use in small offices and classrooms, these projectors are also suitable for displaying video or advertising of products that are fired into the glass counter.