Tuesday, February 22, 2011

New Internet Protocols !!

What users should know about new internet protocols
DPA, On Sunday 20 February 2011, 10:21 AM
Berlin, Feb 20 (DPA) Many web surfers don't know it, but the introduction of new internet address standards might change the way they get online.
Since the supply of usable addresses governed by the IPv4 standard (internet protocol, version 4) has been exhausted, IPv6 has now been introduced. This will allow a previously impossible variety of addresses, says Christoph Meinel, a professor at Germany's Hasso Plattner Institute.
But what does this change mean for everyday surfers? Here's an overview.
Why are IP addresses necessary?
In order for internet-capable devices to share information, they need a unique machine-readable address. These addresses are assigned based on a standard of internet protocols.
But, since humans have a hard time remembering these strings of numbers, websites are also labelled with domain names, like When these addresses are typed into browsers, special servers translate them into IP addresses for the benefit of the computers.
What is the difference between IPv4 and IPv6?
Until now, IP addresses have been assigned in blocks of four numbers with up to three numerals each:, for example. The new IPv6 standard won't convert the numbers into the decimal system, rather a hexadecimal system, recognized by its combination of numbers and letters.
The new standard can be recognized by its eight blocks, separated by colons - 2001:db8:0:0:0:0:1428:57ab, for example.
Will my computer be able to process the new standard?
In most cases, yes. But an IPv6-capable operating system is a prerequisite. Those can be found in any Windows system post Vista. There are ways to install the functionality into Windows XP systems. Mac systems starting at 10.2 and Linux, in general, can support IPv6.
Will my DSL access support the new standard?
In most cases, no. Contemporary routers, like the ones provided by telecommunications companies when DSL packages are ordered, are still set for the old IPv4 standard. In some cases, IPv6 can be added with a firmware update. When purchasing a new router, make sure it supports IPv6.
Should I anticipate problems during the transition to the new standard?
Generally, no. Internet use shouldn't be affected after the switch - at least that's what providers are promising. Those providers have modified their network so that data packets reach all users whether they are using IPv4 or IPv6 standards, a method called dual-stack application. Alternatively, software solutions, like those based on tunnel technology, can be used. 

Friday, February 4, 2011


Degradaation  can be classified in two ways:

• According to the way that they degrade, for example whether they require the actions of microorganisms (i.e. are biodegradable), or whether they require heat, ultraviolet light, mechanical stress or water in order to break down; and

• According to the materials they are manufactured from, for example whether they are made from natural polymers, synthetic polymers or from a blend of a conventional polymer with an additive to facilitate degradation.

There are five different types of degradable polymers:

  1. Biodegradable polymers are those that are capable of undergoing decomposition into carbon dioxide, methane, water, inorganic compounds or biomass in which the predominant mechanism is the enzymatic action of micro-organisms that can be measured by standardized tests, in a specified time, reflecting available disposal conditions.

  1. Compostable polymers are those that are degradable under composting conditions. To meet this definition they must break down under the action of micro-organisms (bacteria, fungi, algae), achieve total mineralization (conversion into carbon dioxide, methane, water, inorganic compounds or biomass under aerobic conditions) and the mineralization rate must be high and compatible with the composting process.

  1. Oxo-biodegradable polymers are those that undergo controlled degradation through the incorporation of ‘prodegradant’ additives (additives that can trigger and accelerate the degradation process). These polymers undergo accelerated oxidative define degradation initiated by natural daylight, heat and/or mechanical stress, and embrittle in the environment and erode under the influence of weathering.

  1. Photodegradable polymers are those that break down through the action of ultraviolet (UV) light, which degrades the chemical bond or link in the polymer or chemical structure of the plastic. This process can be assisted by the presence of UV-sensitive additives in the polymer.

  1. Water-soluble polymers are those that dissolve in water within a designated temperature range and then biodegrade in contact with microorganisms.

(The composition of degradable bags also varies, with the main categories)
  1. Thermoplastic starch-based polymers, made with at least 90% starch from renewable resources such as corn, potato, tapioca or wheat.

  1. Polyesters, manufactured from hydrocarbons (oil or gas). All polyesters degrade eventually, with degradation rates ranging from weeks for aliphatic polyesters (e.g. polyhydroxyalkanoates) to decades for aromatic polyesters (e.g. PET).

  1. Starch – polyester BLENDS that mix thermoplastic starch with polyesters made from hydrocarbons.