Daily Archives: May 24, 2019

Trading Tickers – Insights

Image result for trading tickers dvdGetting familiar with recordable DVD formats
Probably everyone nowadays had a need to transfer information between several PC’s or make a backup copy of favorite movie. Recordable DVDs (DVD-Rs) serve this purpose very well, but it could be quite hard to get familiar with all the different types of them. While in CD era there were only two formats, namely CD-R for recordable and CD-RW for rewritable disk, for DVD it is not that simple. The fight between manufacturers to enforce their own formats led to the mess of the biblical scale. Besides DVD-R and DVD-RW, in most shops it is possible to encounter DVD+R, DVD+RW and even mysterious DVD-RAM. And there is no guarantee that your DVD drive will be able to work with newly purchased disk.Have a look at trading tickers dvd for more info on this.

In this article we will try and help users to get familiar with this mess.


(DVD Read Only Memory). Generic factory-printed DVD. All mass-production DVDs with movies, software etc are printed on DVD-ROM.

(DVD-Recordable – pronounced as “DVD Are” or “DVD Dash Are”). This is the first format for recordable DVDs. It was developed in 1995 by Pioneer and was approved by DVD-Forum as a main standard for recordable DVD. Basically, this formatis direct analogue of CD-R but with bigger capacity and, respectively, smaller track size. As with CD-R, record is made by altering the structure of organic polymer in reflective layer with powerful laser. DVD-R can be recorded only once, but it is compatible with most DVD players and computer DVD drives. Properly stored and unscratched DVD is believed to remain readable for hundreds of years.

Initially DVD-R was only single-layered, but recently double-layer DVD-R DL (dual layer) becomes available. They are also known as DVD-R9, however, they are still uncommon and they can be recorded only on newest models of DVD burners. Trying to record these disks in non-compatible drive can actually lead to the DVD burner damage.

There are two types of DVD-R disks: DVD-R Authoring (DVD-R (A)) and DVD-R General (DVD-R (G)).DVD-R (A) type of disks appears first and was used only for professional needs. This type of disk allows recording of anything, including hidden area and keys, which means that It can be used as a master-copy for mass-production.

Devices and disks compatible with DVD-R(A) are professional equipment and therefore very expensive and uncommon.
DVD-R General (G) is much more common. It was developed later specifically for the needs of common users. This type of disks does not allow making a full copy of protected DVD – no keys will be recorded and resulting disk simply will not play. On the other hand, there are lots of devices and blank DVD-R son the market for this type of disks, and they also quite inexpensive. DVD-R (G) devices can read DVD-R (A) disks but cannot record anything on them.

Image result for trading tickers dvdUnlike CD-R, DVD-R shave a special copy protection called CPRM, which stands for Content Protection for Recordable Media. Each blank DVD-R has inerasable encrypted entry (lead in) in hidden area of the disk, which contains information about type of medium and manufacturer. When backup copy of protected DVD is made, copy program will re-encode the information again, but this time using this hidden information, so twill not be possible to copy the resulting disk again as it will require hidden information from specific medium. This type of copy protection also supported by other DVD-Forum formats, namely DVD-RW and DVD-RAM.

DVD-RW (DVD ReWritable) was also developed by the Pioneer and essentially is the same DVD-R with only difference that reflective layer’s state can be transformed by the laser more than once. The specifications for DVD-RW states that each DVD-RW medium should withstand up to 1000 rewriting cycles. The reflectivity of DVD-RWs is much less then of DVD-R and some DVD drives can mistake them for dual-layer DVD. For this reason DVD-RW are compatible with only approximately 70% of existing DVD players.

Features Of Liquid Level Sensing Technologies-Guidelines

The simplest method of measuring liquid level is through direct observation, but this doesn’t happen in industrial areas, where containers are huge and sealed and cannot be opened without proper resource and safety precautions. Hence a liquid level indicator is used to measure and monitor the liquid level for proper and smooth functioning of all industrial processes. An ultrasonic level indicator is the most advanced and easy method for monitoring levels of liquid in various industrial sectors and plants, as well in household applications. It is considered highly functional and health friendly for measuring liquid content in specific areas:check over here

Applications and Usage

For the measurement of corrosive chemical liquids in chemical plants that cannot be opened directly for safety reasons. For detecting the presence of fluids in standing pipes, particularly to investigate pipes that are being opened for maintenance reasons. For the measurement of fluid levels in automotive components, such as fuel tanks, transmission assemblies and engine oil pans. An ultrasonic level indicator is considered best to measure the layers of different liquid fluids on top of a second liquid. For example, in Petroleum processing system, this liquid level indicator is used to measure the layer of oil over the layer of water. It is used in different fire extinguishing cylinders and sprinkler systems to measure the content of cooling agents.

Unsuitable Factors for Ultrasonic Level Indicator

The performance of an ultrasonic level indicator can be affected by different factors like: If the surface of the container wall is pitied and corroded, it may distort the transmission of the sound pulse back to the transducer, bringing changes in measurement. Curvature of container also plays an essential role in getting the correct measurements of liquid level. If it sharply curved, it may distort sound pulses or cause poor coupling of the transducer to the container. As ultrasonic sound waves travel in straight line, it is essential to clear the sound path of waves of any obstructions such as baffles or fill pipes, to prevent false return of the sound waves.

Acoustic properties of the liquid may also cause change in ultrasonic measurements. Generally liquid of high viscosity or movement of liquid inside the container may also change the viscosity of liquid, thus causing variations in measurement. A constant is essential to getting the right liquid level measurement. Any change in temperature may change the sound velocity of liquid, and may not give the correct readings on ultrasonic level indicator. Other factors like foam, gas bubbles, steam and surface turbulence also causes change in the measurements. Gas bubble inside the container will scatter sound waves and give false readings; steam and turbulence may absorb the sound waves and give incorrect readings.

How to overcome these factors?

The best location to mount an ultrasonic liquid level indicator is usually at the top middle of container, where the sound waves may travel directly in straight line to the liquid surface. Install an ultrasonic level indicator in a stand pipe to prevent changes in temperature, and to keep ultrasonic sound waves away from any foam, steam, gas bubbles or other obstructions. For a slopped or dome shaped tank, use a plastic self-aligning bulk heading to let the sensor keep moving in accordance with the liquid surface.