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The rapid emergence of USB memory sticks has taken the market by surprise. The technology and flexibility of the USB portable devices is increasing on a massive scale. Approximately 116 million of these devices were shipped by manufacturers in 2006. This is an increase of over 25 percent from the preceding year. In 2007, experts predicted the sales of removable memory sticks to increase by almost 300 percent.
In uninterruptible power supply (UPS) installations, ‘discrimination’ is a term used to describe the co-ordination of protective devices within a supply circuit to ensure any load developing a fault (through overload, short-circuit or earth fault) is isolated and removed in the shortest possible time without disruption to remaining loads. It also ensures protection of supply conductors.
The batteries within an uninterruptible power supply (UPS) are the heart and lungs of its ability to ride through short duration interruptions, keep loads up and running whilst another source or back up power (such as diesel generator) starts up, or to power through automatic shutdown routines.
UPS batteries must be sized to provide a specified runtime, usually measured in minutes or hours, at a specific Watts, kW or MV load. These load-specific factors are incorporated into a battery sizing algorithm that also takes into account a number of criteria such as ambient temperature and the inverter and system efficiencies of the uninterruptible power supply to which they are applicable.
Whilst battery manufacturers provide discharge curves and tables to assist selection, expert UPS manufacturers utilise bespoke battery sizing software programs designed around their own products’ characteristics. Battery packs also tend to be uniform, based around particular types and ranges of battery and manufacturers’ own battery cabinets or stands.
The uninterruptible power supply and battery set combination in a solution will be the nearest matching the calculated load. For example, for a total load (including UPS losses) of 20kW, the nearest matching UPS is a 30kVA/24kW system. Provision of a runtime of 30 minutes in this scenario would require the nearest battery option to be, say, a 38Ah battery set, which would provide 25 minutes at 24kW or 33 minutes at 20kW.
Several factors must be considered when sizing a battery set for an uninterruptible power supply. In particular, site power history is important in determining the depth, frequency and likelihood of mains power failures. The size of critical loads needs to be determined. If there is a maintained standby generator on site, this needs to be taken into consideration. How much runtime is needed to cover load shedding and/or an orderly shutdown? Thought must be be given to the immediate environment; how much available floor and rack space is there, for example, and is it a hot, humid environment or a cold, dry one? Cost implications also have to be factored in, particularly in a tight economic climate where cost-reduction is a must. What is the comparative cost, for example, of installing a number of battery strings to achieve particular runtime duration verses an individual standby generator or fuel cell?
Comparisons between runtime performances of different uninterruptible power supply manufacturers can be misleading. Firstly, comparing battery runtime performance between them is difficult without a common basis. The best solution is to ensure all runtimes are quoted using the same formula - load/Watt ratings and load power factors. An example could be: a 10kVA UPS supporting an 8kW load at 0.8pF, the runtime from a 12Ah internal battery set would be 14 minutes. However, at 75 percent load (6kW) and 0.6pF, the same UPS would provide almost 20 minutes of runtime.
It is possible to estimate battery set sizing, which may be useful for budgetary purposes at the specification stage of a power protection project, but as it is so critical to the overall performance and resilience of the uninterruptible power supply system, battery set sizing at the design stage should be carried out by industry professionals to achieve accurate and reliable ratings.
Parallel uninterruptible power supplies can be installed with a single or dual ac input. It is imperative, however, that the input supply is correctly rated and cabling sized appropriately. The overall rating for a parallel system must be adequate to supply the chosen method of parallel operation, be it a parallel-capacity or parallel-redundant system.
Compared to Intel or AMD, Sun Microsystems has traditionally focused more on high-end, high-powered servers and supercomputers than on desktop home computers. It should come as no surprise, then, that Sun produces some of the most advanced High-performance computing (HPC) systems available. In fact, they offer not just one, but several different types of HPC solutions for different computing needs.
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USB memory sticks are a wonderful way to back up and transport a range of digital information, from music to video to documents to pictures. The only question is, when you are ready to retire your memory stick, how do you dispose of it? Before you think about just throwing away your USB memory stick, consider the myriad ways you can recycle or reuse it.
Before you find an outlet for your old memory sticks, make sure all the information you wrote onto the stick has been properly and completely deleted. While deleting the files yourself at home may appear to remove the information from the stick, the data may still be accessible to skilled hackers and certain spy programs. The best practice is to take the drive to your local computer store or maintenance location and have them professionally delete the information.
A great way to dispose of your memory stick is to donate it. For example, some companies collect unwanted and old USB sticks and recycles them for students and professionals in developing countries who do not have access to such technology. Some education trusts also accepts donated USB memory sticks in support of schools in Africa. If you prefer your donation to stay more local, then some local libraries distribute audio books to the blind on donated memory sticks.
If you do not like the idea of donating your USB memory stick, it is also possible to recycle your memory stick at home by finding alternative uses for them. Unwanted USB sticks can be used as key chain charms or plant labels. The circuit boards and interior wiring can be reconfigured and redesigned to make unique jewelry pieces, and an arrangement of USB parts could contribute to an art project. Some people grind up their old USB sticks and lay it around flower beds as moisture insulation and weed protection. All you need to recycle your memory stick at home is a little imagination!
A final resort for the disposal of unwanted USB memory sticks is throwing them away but make sure to heed the warning about deleting all information properly before choosing this disposal option!
Everything considered, the best disposal method is reuse. One of the best aspects of a USB memory stick is it can be rewritten again and again and continue to hold and transport your data in a small and efficient manner and with sales of these units in the hundreds of millions they are likely to be here for quite some time yet.
Innovative usb memory sticks have changed our lives in the way that we humans communicate with the machine. USB memory sticks revolutionized the computer industry by offering a faster method to transfer data between two devices. The Plug & Play technology is the foremost example of its success. Among the multiple benefits, the USB memory sticks have paved the way for a portable disk storage solution. There is no more a need to carry diskettes, discs and similar storage devices as these memory sticks are able to store huge amount of data easily transferable from one computer to another.
The external hard disk drive is the form of the internal hard drive and can be connected to the computer system through the data (external) cables. Auxiliary power is required by some of the external hard drives and the other drives get the power from the USB 2.0 data connection. The external hard drives provide the facility to the users as an excellent backup hardware due to its portability and the capabilities of data storage. The external USB drives also have different sizes and shapes like the internal hard drives.
It’s common nowadays to produce positves for screenprint on a high-end inkjet printer. The inkjet printers are standard issue, usually Epson manufacture, with 6,7 or more inks. It is possible, with the correct set-up to run high quality proofs from these devices.