Continent

Seven Continent

 

5 Ocean

 Pacific Ocean

The Pacific Ocean is the largest ocean. The Pacific Ocean covers 69,375,000 square miles, or 35% of the earth. The Pacific Ocean is almost half of all the oceans, as big as the other four oceans combined. As the earth spins around, there is a viewpoint from outer space where all you can see is the Pacific Ocean. The Pacific Ocean is between Asia on the west and North and South America on the east. The Pacific Ocean connects to the Indian Ocean to the west, to the Antarctic Ocean to the south, and to the Arctic Ocean to the north.

Atlantic Ocean

The Atlantic Ocean is the second largest ocean. The Atlantic Ocean covers 41,105,000 square miles, or 21% of the earth. The Atlantic Ocean is a little bigger than half as big as the Pacific Ocean. The Atlantic Ocean is between North and South America on the west and Europe and Africa on the east. The Atlantic Ocean connects to the Arctic Ocean to the north, and to the Antarctic Ocean to the south.

Indian Ocean

The Indian Ocean is the third largest ocean. The Indian Ocean covers 28,900,000 square miles, or 15% of the earth. The Indian Ocean is between Africa on the west and Asia on the north. The Indian Ocean connects to the Antarctic Ocean to the south, and to the Pacific Ocean to the east.

Antarctic Ocean

The Antarctic Ocean circles the globe and surrounds the southern continent of Antarctica. The Antarctic Ocean is also called the Southern Ocean. The Antarctic Ocean is connected to the Atlantic, Indian, and Pacific Oceans.

Arctic Ocean

The Arctic Ocean covers the earth's north pole. This ocean is so cold that its surface is often frozen during the winter. The vast Arctic icecap is the source of many icebergs. The Arctic Ocean is between North America and Asia. The Arctic Ocean is connected to the Atlantic and Pacific Oceans.

 Longitude & Latitude

Reverse osmosis

Osmosis is the tendency of fluids to pass through a membrane with equal concentrations on both sides.

Reverse osmosis is forcing fluids through a membrane with a lower concentration on one side than the other.

How the Reverse Osmosis System Works?

Reverse Osmosis is a process in which dissolved inorganic solids (such as salts) are removed from a solution (such as water). This is accomplished by household water pressure pushing the tap water through a semi permeable membrane. The membrane (which is about as thick as cellophane) allows only the water to pass through, not the impurities or contaminates. These impurities and contaminates are flushed down the drain.

Ultimately, the factors that affect the performance of a Reverse Osmosis System are:

• Incoming water pressure
  
• Water Temperature
  
• Type and number of total dissolved solids (TDS) in the tap water
  
• The quality of the filters and membranes used in the RO System (see operating specs) 

Source:- http://espwaterproducts.com

FET vs MOSFET

The transistor, a semiconductor device, is the device that made all our modern technology possible. It is used to control the current and even to amplify it based on an input voltage or current. There are two major types of transistors, the BJT and the FET. Under each major category, there are many subtypes. This is the most significant difference FET and MOSFET. FET stands for Field Effect Transistor and is a family of very different transistors that collectively rely on an electric field created by the voltage on the gate in order to control the current flow between the drain and the source. One of the many types of FET is the Metal-Oxide Semiconductor Field Effect Transistor or MOSFET. The Metal-Oxide Semiconductor is used as an insulating layer between the gate and the substrate of the transistor.

The oxide insulation in most MOSFETs nowadays is Silicon Dioxide. It might seem confusing as silicon is not a metal but a metalloid. Initially, a metal was actually used but has been replaced with Silicon due to its superior characteristics. The Silicon Dioxide is basically a capacitor that holds charge whenever voltage is applied to the gate. This charge then creates a field by pulling oppositely charged particles or repelling particles with the same charge and allows or restricts the flow of the current between the drain and source.

Although there are a wide number of transistors that can be used in digital circuitry, it is the MOSFET that is currently preferred. CMOS (Complementary Metal-Oxide Semiconductor) basically uses a p-type and n-type MOSFETs in pairs to complement each other. In this configuration, MOSFETS only have significant power consumption during switching and not while it holds its state. This is very desirable, especially in modern computing equipment where power and thermal limits are pushed to the edge. Other types of FET cannot replicate this capability or are too expensive to manufacture.

Advancements in MOSFETs are constantly evolving, both in size as companies keep going into smaller architectures. But also in design like the 3D MOSFETs that show a lot of promise. MOSFETs are the transistor of choice for today as researchers try to find other types of transistors that can be a suitable replacement for it.

Summary:

1.MOSFET is a type of FET
2.MOSFET is the preferred type of FET for digital circuitry

Source: www.differencebetween.net

Introduction of the semiconductor fabrication processing

IC-manufacturing process is a multiple-step sequence of photographic and chemical processing steps during which electronic circuits are gradually created on a wafer made of pure semiconducting material. Figure 1 illustrates one cycle of the main steps and their sequence. The final products will come out after repeating several times this basic cycle. And wafer cleaning is happening throughout the whole fabrication process.

The main steps of the semiconductor manufacturing are Layering ,Photo-lithography,Etching,Doping,Resist removal and Wafer cleaning.
Layering techniques are used to grow thin layers of film on the surface of a silicon wafer.
Photo-lithography is a process used in micro fabrication to selectively remove parts of a thin film (or the bulk of a substrate). It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical (photo-resist) on the substrate.
Etching is the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio in the metal.
Doping refers to the process of introducing impurity atoms into a semiconductor region in a controllable manner in order to define the electrical properties of this region
After the etching or ion implantation step, the photoresist needs to be stripped away.
Cleaning techniques are used to remove particulates and chemical impurities so contaminant-free surfaces can be obtained. However, such cleaning-methods must also be able to do this without damaging the surface.



Source http://blog.associatie.kuleuven.be