Nanoscale Materials

	Nanoscale materials have feature size less than 100 nm – utilized in nanoscale structures, devices and systems Nanoparticles and Structures Silver Nanoparticles Gold Nanoparticles

Nanotechnology Health and Environmental Concerns

−     Human and the environment come under exposure to nanomaterials at different stages of the product cycle −     Nanomaterials have large surface to volume ratio and novel physical as well as chemical properties which may cause them to pose hazards to humans and the environment −     Health and the environmental impacts associated with the exposure to many of the engineered nanomaterials are still uncertain −     The environmental fate and associated risk of waste nanomaterials should be assessed – e.g. toxic transformation, and interactions with organic and inorganic materials

Nanotechnology Applications

Information Technology •       Smaller, faster, more energy efficient and powerful computing and other IT-based systems Medicine •       Realization of miniaturized devices and systems while providing more functionality •       Cancer treatment •       Bone treatment •       Drug delivery •       Appetite control •       Drug development •       Medical tools •       Diagnostic tests •       Imaging Energy •       More efficient and cost effective technologies for energy production −      Solar cells −      Fuel cells −      Batteries −      Bio fuels Consumer Goods •       Foods and beverages −     Advanced packaging materials, sensors, and lab-on-chips for food quality testing •       Appliances and textiles −     Stain proof, water proof and wrinkle free textiles •       Household and cosmetics −      Self-cleaning and scratch free products, paints, and better cosmetics

Nanoscale Size Effect

•       Realization of miniaturized devices and systems while providing more functionality •       Attainment of high surface area to volume ratio •       Manifestation of novel phenomena and properties, including changes in: -  Physical Properties (e.g. melting point) -  Chemical Properties (e.g. reactivity) -  Electrical Properties (e.g. conductivity) -  Mechanical Properties (e.g. strength) -  Optical Properties (e.g. light emission

History of Nanotechnology

•       2000 Years Ago – Sulfide nanocrystals used by Greeks and          Romans to dye hair            •       1000 Years Ago (Middle Ages) – Gold nanoparticles of different sizes used to produce different colors in stained glass windows •       1974 – “Nanotechnology” - Taniguchi uses the term                      nanotechnology for the first time •       1981 – IBM develops Scanning Tunneling Microscope                   •       1985 – “Buckyball” - Scientists at Rice University and University of Sussex discover C60 •       1986 – “Engines of Creation” - First book on  nanotechnology by K. Eric Drexler.       Atomic Force Microscope  invented by Binnig, Quate and Gerbe   •       1989 – IBM logo made with individual atoms                                                                   •       1991 – Carbon nanotube discovered by S. Iijima                                                              •       1999 – “Nanomedicine” – 1st nanomedicine  book by R. Freitas                                    •       2000 – “National Nanotechnology Initiative” launched

What is Nanotechnology

Header 1	Nanotechnology is the creation of functional materials, devices and systems, through the understanding and control of matter at dimensions in the nanometer scale length (1-100 nm), where new functionalities and  properties of matter are observed and harnessed for a broad range of applications

OSI REFERENCE MODEL

Introduction Advantages Networking Goals Networking Criteria Applications Common Terminology Used In Internet Network Topologies Types of Network LOCAL AREA NETWORK LAN Transmission Methods LAN Topologies LAN Devices Networking Basics OSI REFERENCE MODEL

The Layers:- Think of the seven layers as the assembly line in the computer. At each layer, certain things happen to the data prepare it for the next layer. The seven layers, which separate into two sets, are: Application Set Layer 7: Application-    This is the layer that actually interacts with the operating system or application whenever the user chooses to transfer files, read messages or perform other network-related activities.    Layer 6: Presentation- Layer 6 takes the data provided by the Application layer and converts it into a standard format that the other layers can understand.                                  Layer 5: Session- Layer 5 establishes, maintains and ends communication with the receiving device. Transport Set Layer 4: Transport- This layer maintains flow control of data and provides for error checking and recovery of data between the devices. Flow control means that the Transport layer looks to see if data is coming from more than one application and integrates each application’s data into a single stream for the physical network. Layer 3: Network- The way that the data will be sent to the recipient device is determined in this layer. Logical protocols, routing and addressing are handled here. Layer 2: Data- In this layer, the appropriate physical protocol is assigned to the data. Also, the type of network and the packet sequencing is defined. Layer 1: Physical- This is level of the actual hardware. It defines the physical characteristics of the network such as connections, voltage levels and timing. <<Previous Page                                      Main Page>>

NETWORKING BASICS

Introduction Advantages Networking Goals Networking Criteria Applications Common Terminology Used In Internet Network Topologies Types of Network LOCAL AREA NETWORK LAN Transmission Methods LAN Topologies LAN Devices Networking Basics OSI REFERENCE MODEL

Here are some of the fundamental parts of a network:       Network: A network is a group of computers connected together in a way that allows information to be exchanged between the computers.               Node: A node is anything that is connected to the network. While a node is typically a computer, it can also be something like a printer or CD-ROM tower.         Segment: A segment is any portion of a network that is separated, by a switch, bridge or router, from other parts of the network.       Backbone: The backbone is the main cabling of a network that all of the segments connect to. Typically, the backbone is capable of carrying more information than the individual segments. For example, each segment may have a transfer rate of 10 Mbps (megabits per second), while the backbone may operate at 100 Mbps. Topology: Topology is the way that each node is physically connected to the network (more on this in the next section). Local Area Network (LAN): A LAN is a network of computers that are in the same general physical location, usually within a building or a campus. If the computers are far apart (such as across town or in different cities), than a Wide Area Network (WAN) is typically used. Network Interface Card (NIC): Every computer (and most other devices) is connected to a network through an NIC. In most desktop computers, this is an Ethernet card (normally 10 or 100 Mbps) that is plugged into a slot on the computer’s motherboard. Media Access Control (MAC) Address: This is the physical address of any device such as the NIC in a computer on the network. The MAC address, which is made up of two equal parts, is 6 bytes long. The first 3 bytes identify the company that made the NIC. The second 3 bytes are the serial number of the NIC itself.          <<Previous Page                         Next Page>>

LAN Devices

Introduction Advantages Networking Goals Networking Criteria Applications Common Terminology Used In Internet Network Topologies Types of Network LOCAL AREA NETWORK LAN Transmission Methods LAN Topologies LAN Devices Networking Basics OSI REFERENCE MODEL

Devices commonly used in LANs include repeaters, hubs, LAN extenders, bridges, LAN switches, and routers. A Repeater us a physical layer device used to interconnect the media segments of an extended network. A repeater essentially enables a series of cable segments to be treated as a single cable. Repeaters receive signals from one network segment and amplify, retime, and retransmit those signals to another network segment. These actions prevent signal deterioration caused by long cable lengths and large numbers of connected devices. Repeaters are incapable of performing complex filtering and other traffic processing. In addition, all electrical signals, including electrical disturbances and other errors, are repeated and amplified. The total number of repeaters and network segments that can be connected is limited due to timing and other issues. Figure illustrates a repeater connecting two network segments. Figure: A Repeater Connects Two Networks Segments A Hub is a physical layer device that connects multiple user stations, each via a dedicated cable. Electrical interconnections are established inside the hub. Hubs are used to create a physical star network while maintaining the logical bus or ring configuration of LAN. In same respects, a hub functions as a multi-port repeater. Switches are another fundamental part of many networks because they speed things up. Switches allow different nodes (a network connection point, typically a computer) of a network to communicate directly with one another in a smooth and efficient manner. There are many different types of switches and networks. Switches that provide a separate connection for each node in a company’s internal network are called LAN switches. Essentially, a LAN switch creates a series of instant networks that contain only the two devices communicating with each other at that particular moment. <<Previous Page                            Next Page>>

LAN Topologies

Introduction Advantages Networking Goals Networking Criteria Applications Common Terminology Used In Internet Network Topologies Types of Network LOCAL AREA NETWORK LAN Transmission Methods LAN Topologies LAN Devices Networking Basics OSI REFERENCE MODEL

LAN topologies define the manner in which network devices are organized. Fore common LAN topologies exist: Bus, Ring, Star, and Tree. These topologies are logical architectures, but the actual devices need not be physically organized in these configurations. Logical bus and Ring topologies, for example, are commonly organized physically as a Star. A Bus topology is a linear LAN architecture in which transmission from network stations propagate the length of the medium and are received by all other stations. Of the three most widely used LAN implementations, Ethernet/IEEE 802.3 networks-including 100 Base T-implement a bus topology, which is illustrated in Figure. A Ring Topology is a LAN architecture that consists of a series of devices connected to one another by unidirectional transmission links to form a single closed loop. Booth Token Ring/IEEE 802.5 and FDDI (Fiber Distributed Data Interface) networks implement a ring topology. Figure depicts a logical ring topology. Figure: Some networks Implement a Logical Ring Topology A Star Topology is a LAN architecture in which the endpoints on a network are connected to a common central hub, or switch, by dedicated links. Logical bus and ring topologies are often implemented physically in a star topology. A Tree Topology is a LAN architecture that is identical to the bus topology, except that branches with multiple nodes are possible in this case. Figure illustrates a logical tree topology. Figure: A Logical Tree Topology Can Contain Multiple Nodes <<Previous Page                                      Next Page>>