Friday, December 3, 2010

**** The five examples ofstorage devices ****


1.Hard disk drive

Hard disk drive
Hard disk platters and head.jpg
Interior of a hard disk drive
Date invented December 14, 1954[1]
Invented by An IBM team led by Rey Johnson

A hard disk drive[2] (HDD) is a non-volatile, random access device for digital data. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read and written on the platter by read/write heads that float on a film of air above the platters.
The first HDD was invented by IBM in 1956. They have fallen in cost and physical size over the years while dramatically increasing capacity. Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s.[3] They have maintained this position because advances in their areal recording density have kept pace with the requirements for secondary storage.[3] Form factors have also evolved over time from great standalone boxes to today's desktop systems mainly with standardized 3.5-inch form factor drives, and mobile systems mainly using 2.5-inch drives. Today's HDDs operate on high-speed serial interfaces; i.e., serial  ATA  (SATA) or serial attached SCSI (SAS)

 

 

2.Buffalo network-attached storage series


 



Buffalo network-attached storage series
Kuro-box pro.jpg
The Kuro-Box Pro
Manufacturer Melco
Type Network-attached storage
Operating system Linux
CPU PowerPC, MIPSel, ARM
Connectivity 100BASE-T, 1000BASE-T
The Buffalo network-attached storage series are network-attached storage devices.[1] They can be modified[2] into miniature general purpose Linux-based computers. The LinkStation and TeraStation are intended for the general public, while the Kuro Box is intended for expert hackers as a cheap platform for Linux development.

3.Carbon capture and storage


 



Schematic showing both terrestrial and geological sequestration of carbon dioxide emissions from a coal-fired plant
Carbon capture and storage (CCS), alternatively referred to as Carbon capture and sequestration, is a means of mitigating the contribution of fossil fuel emissions to global warming, based on capturing carbon dioxide (CO2) from large point sources such as fossil fuel power plants, and storing it in such a way that it does not enter the atmosphere. It can also be used to describe the scrubbing of CO2 from ambient air as a geoengineering technique.
"Carbon capture and storage" has also been used to describe biological capture and subsequent storage of atmospheric CO2, such as the burial of "biochar"—the end product of "pyrolysis", the decomposition of organic material by heat in the absence of oxygen. However, the term is more conventionally applied to non-biological methods of capturing carbon dioxide from combustion at the source.
Although CO2 has been injected into geological formations for various purposes, the long term storage of CO2 is a relatively new concept. The first commercial example is Weyburn in 2000;[1] integrated pilot-scale CCS power plant was to begin operating in September 2008 in the eastern German power plant Schwarze Pumpe run by utility Vattenfall, in the hope of answering questions about technological feasibility and economic efficiency.
CCS applied to a modern conventional power plant could reduce CO2 emissions to the atmosphere by approximately 80-90% compared to a plant without CCS.[2] The IPCC estimates that the economic potential of CCS could be between 10% and 55% of the total carbon mitigation effort until year 2100 (Section 8.3.3 of IPCC report.[2])
Capturing and compressing CO2 requires much energy and would increase the fuel needs of a coal-fired plant with CCS by 25%-40%.[2] These and other system costs are estimated to increase the cost of energy from a new power plant with CCS by 21-91%.[2] These estimates apply to purpose-built plants near a storage location; applying the technology to preexisting plants or plants far from a storage location will be more expensive. However, recent industry reports suggest that with successful research, development and deployment (RD&D), sequestered coal-based electricity generation in 2025 will cost less than unsequestered coal-based electricity generation today.[3]
Storage of the CO2 is envisaged either in deep geological formations, in deep ocean masses, or in the form of mineral carbonates. In the case of deep ocean storage, there is a risk of greatly increasing the problem of ocean acidification, a problem that also stems from the excess of carbon dioxide already in the atmosphere and oceans. Geological formations are currently considered the most promising sequestration sites. The National Energy Technology Laboratory (NETL) reported that North America has enough storage capacity at its current rate of production for more than 900 years worth of carbon dioxide.[4] A general problem is that long term predictions about submarine or underground storage security are very difficult and uncertain and CO2 might leak from the storage into the atmosphere.
When applied on plants which use biomass, the process is known as bio-energy with carbon capture and storage. This has the potential to be used as a negative carbon emission technique, and is by some regarded as geoengineering.



4.Energy storage

The Llyn Stwlan upper reservoir and dam of the Ffestiniog Pumped Storage Scheme in north Wales. The lower power station has four water turbines which can generate 360 MW of electricity within 60 seconds, an example of artificial energy storage and conversion.
Energy storage is accomplished by devices or physical media that store some form of energy to perform some useful operation at a later time. A device that stores energy is sometimes called an accumulator.
All forms of energy are either potential energy (e.g. Chemical thermodynamics, gravitational, electrical energy, etc.) or kinetic energy (e.g. thermal energy). A wind-up clock stores potential energy (in this case mechanical, in the spring tension), a battery stores readily convertible chemical energy to operate a mobile phone, and a hydroelectric dam stores energy in a reservoir as gravitational potential energy. Ice storage tanks store ice (thermal energy) at night to meet peak demand for cooling. Fossil fuels such as coal and gasoline store ancient energy derived from sunlight by organisms that later died, became buried and over time were then converted into these fuels. Even food (which is made by the same process as fossil fuels) is a form of energy stored in chemical form.






Random-access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order (i.e., at random). "Random" refers to the idea that any piece of data can be returned in a constant time, regardless of its physical location and whether it is related to the previous piece of data.[1]
The word "RAM" is often associated with volatile types of memory (such as DRAM memory modules), where the information is lost after the power is switched off. Many other types of memory are RAM as well, including most types of ROM and a type of flash memory called NOR-Flash.




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