A diamond is the world’s exceptionally precious gemstone, but the beauty of colored diamonds is something which every gemstone might crave for. Being the most admirable and rare, colored diamonds are the dream of every investor, collector and connoisseur. It is the most sought after gemstone and an investment of a lifetime. An interesting fact about a colored diamond is that it is the most rarest among 10,000 carats of diamonds. In simple words, only 1 carat are colored out of 10,000 carats.
These fancy diamonds are available in vibrant red, blue, green, purple, yellow and so many other hues. Important factors to be considered while grading colored diamonds are their fancy & vividness, which depends on their color and saturation. The beautiful colors of these diamonds are a result of presence of trace elements within the carbon crystal structure of a diamond.
Common colors found are mentioned below
Yellow : When nitrogen is present as an impurity in the crystal structure of diamond, it appears as yellow color.
Blue and grey : The presence of boron (hydrogen) results in formation of this color.
Green : Green color is due to the ‘vacancy color center’ phenomenon.
Gemology defines it as the vacancy in the atomic structure of carbon.
Pink, mauve,brown : These colors are created by plastic distortion.
In other words, due to disfigurement of the internal frame of the diamond.
The rarity of the colored diamonds is marked by the fact of their 1 percent presence amongst the world’s total diamond. Hence, they can be aptly addressed as priceless. Red is the most rare color found in diamonds and because of rarity, diamonds undergo HPHT treatment- or the High Pressure High Temperature treatment to form color. In this treatment, diamonds are put under high pressure and high temperature to transform the crystal structure and create brown diamonds colorless and diamonds with nitrogen into a deep yellow-green color.
Diamond Jewelry Manufacturers & Suppliers : http://www.indianindustry.com/diamondjewelry/
Colgate Coupon – Save Money With Colgate Coupons
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Toothpaste is one product that is used every day by people all over and Colgate toothpaste is very popular.
Like everything else, toothpaste has become very expensive and coupons can certainly help reduce the cost.
With the credit crunch well and truly upon us, Colgate coupons are a highly searched for phrase and can be found on a few websites.
If you are lucky enough to find a printable Colgate coupon, all you need is a printer and internet connection to print the coupons out.
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All folk are looking to save money especially at this time of year, when many are struggling to make ends meet.
The trick to using coupons is to find the ones you need, either print them straight from your PC or have them emailed to you and make sure you use them before the expiry date.
Colgate coupons are really popular because Colgate toothpaste is excellent quality and the range includes Colgate total protection advanced whitening, advanced clean, advanced fresh gel, clean mint paste, whitening paste, whitening gel, plus whitening liquid and mint stripe gel.
Using coupons becomes a way of life for savvy shoppers and they keep them in date order in a folder next to their shopping list, so never to forget them.
If you like Colgate products, using Colgate coupons is a real bonus.
Enterprise Networking Defined
An enterprise network is a large network comprised of hundreds or thousands of workstations all connected with WAN circuits across many states and/or countries. The components are comprised of network devices, circuits, servers, applications, security and network management that connect employees for the purpose of supporting business processes. It is business processes that make companies profitable. The leveraging of new technologies to reduce costs and increase revenues is a business strategy that many companies have employed recently. That is contrasted with the ” ISP ” market, which refers to companies whose business it is to sell infrastructure, web hosting and application services to small, medium and enterprise companies. Many enterprise companies now rely on Internet Service Providers (ISP) for some or all of the mentioned components that comprise an enterprise network.
Usually all circuits are provisioned with the ISP. Some devices are ISP owned and the servers and applications can be all ISP owned if you have a hosting agreement with them that provides those services. Management and security of your network can be outsourced to an ISP as well, which is becoming popular with many Fortune 500 American Financial Corporations. Examples of that are AT&T and IBM, which offer outsourcing agreements with many different options.
OSI Model
The OSI model was developed years ago as a reference for network protocol and application designers to build their products with an open standard. That would promote a standard for developing network devices, interfaces, applications and services that would work together.
It is a model rather than a specification since it defines layers and services for those layers and how each layer works with the layer above and below it. The model is a representation of how a network operates much the same as a phone call. A phone call from your home to a particular destination requires a physical connection that electrically connects those two locations. When you take your phone off hook to make a call that is similar to Layer 1 physical and Layer 2 data link services. When you dial a number that is a Layer 3 network service or phone number routing. When someone answers the phone call that is similar to Layer 4 transport and Layer 5 session services with talking and listening. The specific language that you are speaking is Layer 6 presentation and Layer 7 application services. Today’s data networks use similar design principles.
Your desktop at work is connected to an application server over a physical media such as unshielded twisted pair (UTP) cable. That Layer 1 service is the electrical signaling from your desktop to a campus switch and from a campus switch to a server. Your desktop network interface card connects your desktop to the network cable and uses a Layer 2 data link protocol such as Ethernet that establishes a connection with the campus switch and defines when that desktop has access to the network. Before sending data, the desktop must know the address of the server to which it is sending data. That is a Layer 3 network service. The Layer 4 transport service establishes a logical connection between server and desktop for coordinating traffic flow. As well Layer 4 does error correction and re-transmission of packets if there are problems with data delivery.With the data connection established it is the Layer 5 session service that maintains a logical connection between application processes at the desktop and server. The formatting of the data for a particular application is a Layer 6 presentation service. Many applications will utilize their own formatting which is something you learn when you open files from different word processing vendors. The application interfaces with the OSI model at Layer 7, which is the application Layer. This level defines an API that applications use to develop their specific applications that will work with that layer.
The development of open industry standards at various Layers of the OSI model has contributed to the proliferation of multi-vendor network integration. Some examples of application Layer services are FTP, Telnet, SNMP and many applications that are used over a typical network. Microsoft has done a lot of work to standardize their Windows platform API so that third party application developers can write programs for that operating system. When you exam Windows 2003, for instance, you will notice that it provides services at Layers 3 – 7 of the OSI model. The argument could be made that Microsoft is involved with Layer 1 and 2 services as well since there are some software drivers for network interfaces that are available from them.
When describing client network software from Microsoft that runs at each workstation, it is describing all of the programs such as protocol stacks, network interface card drivers, and programs that integrate these elements. The network software is typically focused on Layer 1 to Layer 4 while application developers will focus on Layers 5 – 7 of the OSI model. It should be noted that the OSI model is a model which suggests that it provides guidelines for network developers. Some network software such as SNA doesn’t define a network Layer 3. The result is that it isn’t routable and a service such as encapsulation or tunneling must be used at the router for sending data across a network that is using a network layer and associated addressing. An example is integrating an SNA network, which doesn’t have a network Layer with a Windows network, which is using IP network services.
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