Giant Magneto Resistance(GMR)

Magneto Resistance(MR):

Hard Disk(HD):

When I was in 8th standard in 1998 computer era started mainly from MS DOS. In those days learning DOS was quite interesting but it became difficult while remembering all DOS commands. But still we did it by help command. Which has given the list of all necessary commands. In those days Pentium processor's were in big boom. We were unaware of all those things like Names, Speed of computer. Actually our computer class started with How to turn ON the computer and similarly the Turn OFF. But now things are changed. Person too, Computer Miss also.Main topic starts from the below paragraph.

When we heard the name technology,first thing will come to our mind is Computer. As we compare the size of computer in 1950's and now 2010. Lot's of change took place in Size, Speed and Storage of memory. Earlier they were in room size, now we can see notebook, laptop and palmtop's. Its because the change in semiconductor physics,which starts from Vacuum tubes to Microprocessor.

Today mainly I am concentrating on Hard Disk known name for all as it stores the songs, films, documents and necessary data. In scientific way, a hard disk stores information, such as music, in the form of microscopically small areas magnetized in different directions. The information is retrieved by a read-out head that scans the disk and registers the magnetic changes. The smaller and more compact the hard disk, the smaller and weaker the individual magnetic areas. More sensitive read-out heads are therefore required if information has to be packed more densely on a hard disk.

Many research people thinking to keep all universities library books in one hard disk. It will become difficult for them, when the hard disk is having capacity of 160GB. So in place of 160 GB they can have 160 TB[Tera Bytes](3TB is max in 2010 of 102mm in width) it might be possible for them. Of course they came with solution. That is Giant Magneto Resistance(GMR).

In 1988 the Frenchman Albert Fert and the German Peter Grünberg each independently discovered a totally new physical effect – Giant Magnetoresistance or GMR. Very weak magnetic changes give rise to major differences in electrical resistance in a GMR system. A system of this kind is the perfect tool for reading data from hard disks when information registered magnetically has to be converted to electric current. Soon researchers and engineers began work to enable use of the effect in read-out heads. In 1997 the first read-out head based on the GMR effect was launched and this soon became the standard technology. Even the most recent read-out techniques of today are further developments of GMR.


The year 2007 physics Nobel prize is awarded for the technology that is used to read data on hard disks. The technology that it has been possible to miniaturize hard disks so radically in recent years. Sensitive read-out heads are needed to be able to read data from the compact hard disks used in laptops and some music players, for instance.

If GMR is to work, structures consisting of layers that are only a few atoms thick have to be produced. For this reason GMR can also be considered one of the first real applications of the promising field of nanotechnology.

Now a days we are using 520GB hard disks, in that we can save at least one nation all university library books. Beyond our imagination.






To be Contd.............






mpshridhar








Credits:

www.research.ibm.com/research/gmr.html

Wikipedia for necessary information.

Google for Images.

Daily Science News Paper

Birds Move in Unison (BMU)

"Bird flock"

If we remember our childhood, we will find some wonderful's of Mother Nature.
1) When we were walking on river shore, we will find many fishes are moving so fast they will not disturb the continuity and speed.
2) When we were sleeping particularly in village, facing towards sky during day time*. Many birds will be travelling in "V" shape. Also we might have seen thousands of birds in a single group with a very high speed.
3) Straight line of Ants when they will find sugar in Kitchen.

In next paragraphs, I am going to discuss with Scientific words.

A flock of birds hundreds strong wheeling in perfect synchrony overhead is one of nature's great sights. If a single bird fell out of line, utter confusion could occurs, yet none does. Harmony reigns, spawning a behavior (flocking, with its swift motion and sudden course changes) that is not predictable from knowing all there is to know about any single bird. Flocking "emerges" from simple rules instinctively followed by each bird: keep a precise distance away from and stay aligned with your nearest neighbors, and avoid predators. The "wave" of people in a stadium operates along similar lines (minus the predator[one who does not take part in making wave] part).

Animal flocks, be it honeybees, fish, ants or birds, often move in surprising synchronicity and seemingly make unanimous decisions at a moment's notice, a phenomenon which has remained puzzling to many researchers.

Now they are ready with answer, which will get support from Physics means from Statistical Mechanics and Quantum Mechanics.

The theory uses a particle model to explain the collective decision making process of flocks of birds landing on foraging flights.

Using a simple self-propelled particle (SPP) system, which sees the birds represented by particles with such parameters as position and velocity,they found that the collective switching from the flying to the landing state overrides the individual landing intentions of each bird.

In the absence of a decision making leader, the collective shift to land is heavily influenced by perturbations the individual birds are subject to, such as the birds' flying position within the flock. For this explanation, we have to consider two polythene bags in which we are going to pour Sand and Grains respectively. Sand will occupy the perfect arrangement but in second bag of Grains, we will find the gap or not perfect as sand.

As the Scientists explain, "Our main motivation was to better understand something which is puzzling and out there in nature, especially in cases involving the stopping or starting of a collective behavioural pattern in a group of people or animals.
"We propose a simple model for a system whose members have the tendency to follow the others both in space and in their state of mind concerning a decision about stopping an activity. This is a very general model, which can be applied to similar situations."

Possible applications include collectively flying, unmanned aerial vehicles, initiating a desired motion pattern in crowds or groups of animals and even finance, where the results could be used to interpret collective effects on selling or buying shares on the stock market.

In Scientists way of thinking which we will call as model. In that model they allow the motivation of individual birds to be influenced by only the observable variables of their neighbours, such as position and velocity and also a method that enables them to work in open boundary conditions where the birds in flight move cohesively and do not spread out in the horizontal plane even in the presence of perturbations. With this model they investigated the level of synchronicity in collective landing
across time and space and explore the nature of fluctuations close to the point in time when birds were flying in flock.

It can be understood from the point of Physics by reading the below mentioned paper.I am remembering my birth place where I saw all these mysteries in my childhood. Walking on, shore of the river. Sleeping in night, facing towards the sky. I used to ask these questions to my aunt, they were unaware of Physics. They used to say God will rule them, god has given order to fly in that way only. Every child will stop asking questions, when someone will say god is the reason for all these things. There the questioning mind will die. But now, we are getting the answers for those questions but we cant explain to our aunts. We learnt Physics they did not. It is easy to convince them. I love them.

Hakki Haratava,
Hari guda seratava,




mpshridhar

* Night also birds will fly in groups.



Credits:

Google for Images and some Information about Bird flocks.

New Journal of Physics 12 (2010) 093019.

News of Sciencedaily.

Cloud Computing(CC)

Quantum Computing(QC):

Cloud is a cause for rain, Cloud Computing is cause for new revolution in the next era. It is applicable only to daily users of computer, banking, accounting etc., Today if we start to use internet, within less than a second you will get the result. Means Internet is fast* its all about the bandwidth and the Optical fiber(OF) communication, on which people are working 24/7. Sometimes even 100Mbps speed will become very slow in front of some good applications. So people are thinking in a new way to increase the speed.

First will come Cloud Computing using softwares or you may say working server.

Second one Scientific people are thinking to pass 100% light through OFC(optical Fibre Cable) till now we are able to pass 68% in low cost. But last year Nobel Prize shared for Optical Fibre Communication in which he passed 98.99% of light, but that technology is costly and we cant use it for applications.

Third one is Wireless Communication: Which comes out from the Transmitter and received by receiver. Essential is again OFC without that no signal can travel in air. Difficult one, people are trying more. Nowadays imagination has crossed the limits, research groups are making electrons to travel in the air. If it became possible next 10 Nobel prizes are for Physics.

So todays topic begins here,

Quantum Algorithm makes Quantum Computer. Which works equally with Supercomputer(India has three one in IISC). According to Tathagat's research papers Quantum Algorithms are the new way for searching or search engines.

Cloud computing is a general term for anything that involves delivering hosted services over the Internet. These services are broadly divided into three categories:
Infrastructure-as-a-Service (IaaS),
Platform-as-a-Service (PaaS) and
Software-as-a-Service (SaaS).
The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams.

A cloud service has three distinct characteristics that differentiate it from traditional hosting. It is sold on demand, typically by the minute or the hour; it is elastic -- a user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider (the consumer needs nothing but a personal computer and Internet access). Significant innovations in virtualization and distributed computing, as well as improved access to high-speed Internet and a weak economy, have accelerated interest in cloud computing.

A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services

Infrastructure-as-a-Service like Amazon Web Services provides virtual server instances with unique IP addresses and blocks of storage on demand. Customers use the provider's application program interface (API) to start, stop, access and configure their virtual servers and storage. In the enterprise, cloud computing allows a company to pay for only as much capacity as is needed, and bring more online as soon as required. Because this pay-for-what-you-use model resembles the way electricity, fuel and water are consumed, it's sometimes referred to as utility computing.

Platform-as-a-service in the cloud is defined as a set of software and product development tools hosted on the provider's infrastructure. Developers create applications on the provider's platform over the Internet. PaaS providers may use APIs, website portals or gateway software installed on the customer's computer. Force.com, and GoogleApps are examples of PaaS. Developers need to know that currently, there are not standards for interoperability or data portability in the cloud. Some providers will not allow software created by their customers to be moved off the provider's platform.

In the software-as-a-service cloud model, the vendor supplies the hardware infrastructure, the software product and interacts with the user through a front-end portal. SaaS is a very broad market. Services can be anything from Web-based email to inventory control and database processing. Because the service provider hosts both the application and the data, the end user is free to use the service from anywhere.

Why Google search engine is in top position from long years. They are having new technologies with respect to time.I am not saying Microsoft's Bing is not having. If we compare with Google then its not. I may say Google adapted Cloud Computing, for its users. But Company has not disclosed any matter regarding this, its because of competition in business. One example,Google is launched new browser Google Chrome, big firms are not worried about browsers, they are worried about search engines. As Mozilla if we would have used, it will ask for add-ins. But the Chrome doesn't asks.The speed changes in both. Chrome is faster.

It may be difficult for Google, Its user, if surfing from any other browser they might have faced the problem to fix the target in Cloud. So its easy way for them to fix the target (Whatever it may be). According to me Big Browser took birth "Google Chrome". If you open Google page it will ask you to install for next uses(No conditions to install). For them it will be the clear road in that we can ride or bike till up to 100Km/Hour. If road is not good, we are having good bike in hand, we cant give the satisfaction to our vehicle. For them, they created good road, choosing bike is your option.

Long one this time, future no posts on CC.


mpshridhar

* Unusual term


Reference:

www.cloudcomputing.com

Google for necessary informations and image(Wikipedia through Google).

http://en.wikipedia.org/wiki/Cloud_computing

www.howstuffworks.com

PHYSICAL REVIEW A 78, 022332 2008

Carbon(C)

Carbon Materials(CM)


Carbon is of prehistoric knowledge as diamond as well as graphite. That diamonds were known at least as early as 1200 B.C. seems probable according to ancient Hindu writings. The earliest authentic reference to the diamond is ascribed to one Manilius near the First Century of our era. The name diamond derives from a corruption of the Greek word adamas "the invincible".

When we were small we know about these things of carbon.(Things include Charcoal, Lantern black of kerosene). At that time these were just a Black materials. Which we should not touch means if we touch with our hands, they will become black, who will go to wash hands. But still it is there in many home as it was first. Because people dont know the value of Carbon. But for many researcher it is like a Magic Wand. It means Carbon made them to think day and night. Due to this result we got more compact and economical devices like Laptop, Cell phones, etc.,



Why today on Black Carbon, as mentioned in my last post Virendra Kumar collects 8 Kg of carbon from his generator. But he will sold that one to local industries. Now my question is for what the local industries need the carbon. They may be using it for different applications(Really I do not know what they do with carbon). But scientifically it can be used for Making Electronic Devices like Diode, Transistor, IC and Batteries nowadays Supercapacitors(Store energy 4 times more than battery and get recharged in lesser duration).


Another thing in physics, it is possible to convert Carbon to Diamond*(Costliest Material & also the form of carbon). Now I want to go for other forms carbon(as much I know). Carbon nano particles, Carbon Nano Tubes(CNT), Carbon Nano Ribbons(CNR), Next comes the Graphene. These were the common materials of Carbon which all Physicist know. Now recently people introduced the carbon onion(Fig 2). Carbon nano onions are the new invention in science. These can be used for many applications like CNT.

We cant explain this to our parents, but we can make them to feel what the household Charcoal and the Lantern Black. If we take (SEM)images of these materials they will be in the form of Nanoparticles, Nano tubes, nano ribbons etc,. they will be wondered if we say 1 Kg of pure Carbon Nano tubes costs of 40,000 Rupees. They will start think how it is so.

Now we will come to the application part of Carbon Nanomaterials. If we used in Batteries as electrodes they will be having large surface area due to that we expect more current and more voltage. If we mix carbon materials with any other Nanoparticles that will work as Electrolyte. So one application is ready. People are thinking to make displays using these materials. Its quite useful to society.

"Negative Points"

No toxic effects appear to be associated with carbon in its elemental form. On the other hand, many of the more commom carbon compounds exhibit strong toxicological effects. Principal among these are carbon monoxide, carbon dioxide, hydrogen cyanide and the alkali cyanides, carbon tetrachloride and carbon disulfide.

Carbon monoxide, an odorless gas, is extremely toxic, behaving as an asphyxiant. Compared to oxygen, it is not only more readily absorved, but also more firmly bound by the hemoglobin of the blood. The capacity of the blood to carry oxygen to the vital parts of the body is thereby reduced, leading to brain damage, heart disease and pneumonia.

Now I will stop this post, in my research work carbon is having little work. finally whatever we burn it will give BLACK MATERIAL i.e Carbon. Please dont consider water for this.

"Time will go,
Day will go,
Carbon will not go
but it will come.
(When you burn any material)"



mpshridhar









*= Necessary to maintain the Physical Conditions which are costlier than the rate of Diamond or little lesser.

Courtesy:Images from google, Negative points from wikipedia.