Ozone is the gas present naturally in the environment. Its chemical formula is O3. In presence of halogens, Ozone (O3) gets converted into Oxygen (O2). Ozone is present in two layers of the atmosphere. About 10% of ozone is present in lower layer of atmosphere (troposphere), which is located at about 6-10 miles from the surface of the earth. Here are some important facts on Ozone:
1. It is created in the upper atmosphere by the action of solar radiation on oxygen molecules.
2. It is found in the form of a thin layer in the stratosphere between 15 and 48 kilometres.
3. Ozone constitutes only less than 0.002 percent of the volume of the atmosphere.
4. About 90% of all atmospheric ozone is found in this layer.
5. It strongly absorbs ultraviolet radiation from the sun.
6. Ultraviolet radiation is biologically destructive in many ways. It causes skin cancer and cataracts, suppresses the human immune system, diminishes the yield of many crops, disrupts the aquatic food chain by killing microorganisms on the ocean surface and many other negative effects which is still undiscovered.
7. Not only is the ozone layer thinning, in some places it has temporarily disappeared.
8. A hole in the layer has developed over Antarctic since 1979 and that hole has persisted for a longer and longer time every year.
9. In 1988, an ozone hole was found over the Arctic for the first time and it too has lasted longer and longer each year since then.10. Ozone depleting substances (ODSs) are widely used in refrigerators, air-conditioners, fire-extinguishers, in dry cleaning, as solvents for cleaning, electronic equipment and as agricultural fumigants. ODSs controlled by Montreal Protocol include: Chlorofluorocarbons (CFCs), Halon; Carbon tetrachloride (CCl4), Methyl chloroform (CH3CCl3), Hydrobromofluorocarbons, Hydrochlorofluorocarbons (HCFCs), Methyl bromide (CH3Br) and Bromochloromethane (CH2BrCl).
What is 5G Technology?
5G simply stands for fifth generation and refers to the next and newest mobile wireless standard based on the IEEE 802.11ac standard of broadband technology, although a formal standard for 5G is yet to be set. And according to the Groupe Speciale Mobile Association (GSMA), to qualify for a 5G, a connection should meet most of these eight criteria:
1. One to 10Gbps connections to end points in the field;
2. One millisecond end-to-end round trip delay;
3. 1000x bandwidth per unit area;
4. 10 to 100x number of connected devices;
5. (Perception of) 99.999 percent availability;
6. (Perception of) 100 percent coverage;
7. 90 percent reduction in network energy usage; and
8. Up to ten-year battery life for low power, machine-type devices.
Previous generations like 3G and 4G were a breakthrough in communications.
3G receives a signal from the nearest phone tower and is used for phone calls, messaging and data. 4G works the same as 3G but with a faster internet connection and a lower latency (the time between cause and effect). 4G claims to be around five times faster than existing 3G services and theoretically, it can provide download speeds of up to 100Mbps.
5G will be significantly faster than 4G, allowing for higher productivity across all capable devices with a theoretical download speed of 10,000 Mbps.
Plus, with greater bandwidth comes faster download speeds and the ability to run more complex mobile internet apps. However, 5G will cost more to implement and while the newest mobile phones will probably have it integrated, other handsets could be deemed out of date.
A reliable, wireless internet connection can depend on the number of devices connected to one channel. With the addition of 5G to the wireless spectrum, this could put us at risk of overcrowding the frequency range.
Application: a programme in which you do your work.
Bit: the smallest piece of information used by the computer. In computer language, it is either a one (1) or a zero (0).
Backup: a copy of a file or disk you make for archiving purposes.
Boot: to start up a computer.
Bug: a programming error that causes a programme to behave in an unexpected way.
Byte: a piece of computer information made up of eight bits.
Card or Expansion Card: a printed circuit board that adds some feature to a computer.
CD-ROM: an acronym for Compact Disc Read-Only Memory.
Control Panel: a programme that allows you to change settings in a program or change the way a computer looks and/or behaves.
CPU (Central Processing Unit): The processing chip that is the “brain” of a computer.
Crash: a system malfunction in which the computer stops working and has to be restarted.
Cursor: The pointer, usually an arrow or cross -shaped, controlled by the mouse.
Desktop: The shaded or coloured backdrop of the screen.
Dialog box: an on-screen message box that appears when additional information is required before completing a command.
Disk: a spinning platter made of magnetic or optically etched material on which data can be stored.
Disk Drive: the machinery that reads the data from a disk and/or writes data to a disk.
Document: a file you create, as opposed to the application that created it.
Download: to transfer data from one computer to another. (If you are on the receiving end, you are downloading. If you are on the sending end, you are uploading).
Driver: a programme on a computer that tells it how to communicate with an add-on piece of equipment (like a printer).
Expansion slot: a connector inside the computer that allows one to plug in a printed circuit board that provides new or enhanced features.
File: the generic word for an application, document, control panel or other computer data.
Floppy Disk: a 3.5-inch square rigid disk that holds data. (Named for the earlier disks that were flexible).
Gigabyte (GB): 1024 megabytes.
Hard Drive: a large capacity storage device made of multiple disks housed in a rigid case.
Icon: a graphic symbol for an application, file or folder.
Kilobyte (K): 1024 bytes.
Launch: start an application.
Megabyte (MB): 1024 kilobytes.
Memory: the temporary holding area where data is stored while it is being used or changed; the amount of RAM a computer has installed.
Menu: a list of programme commands listed by topic.
Menu Bar: the horizontal bar across the top of the screen that lists the menus.
Operating System: the system software that controls the computer.
PC: acronym for personal computer.
RAM (Random-Access Memory): a type of temporary storage that stores information as you use it. It is constantly being erased and rewritten as you open and close files.
ROM (Read Only Memory): it holds important information that the computer needs each time it runs.
Save: to write a file onto a disk.
Save as: (a File menu item) to save a previously saved file in a new location and/or with a new name.
Scroll bar: a bar at the bottom or right side of a window that contains the scroll box and allows scrolling.
Server: a central computer dedicated to sending and receiving data from other computers (on a network).
Shut Down: the command from the special menu that shuts down the computer safely.
Software: files on disk that contain instructions for a computer.
Upload: to send a file from one computer to another through a network.
Lunar Eclipses and Solar Eclipses
An eclipse happens when a planet or a moon gets in the way of the sun’s light. Here on Earth, we can experience two kinds of eclipses: solar eclipses and lunar eclipses.
What’s the difference?
A solar eclipse happens when the moon gets in the way of the sun’s light and casts its shadow on Earth. A total solar eclipse happens about every year and a half somewhere on Earth. A partial eclipse, when the moon doesn’t completely cover the sun, happens at least twice a year somewhere on Earth.
But not everyone experiences every solar eclipse. Getting a chance to see a total solar eclipse is rare. The moon’s shadow on Earth isn’t very big, so only a small portion of places on Earth will see it. You have to be on the sunny side of the planet when it happens. You also have to be in the path of the moon’s shadow.
On average, the same spot on Earth only gets to see a solar eclipse for a few minutes about every 375 years!
During a lunar eclipse, Earth gets in the way of the sun’s light hitting the moon. It means that during the night, a full moon fades away as Earth’s shadow covers it up.
The moon can also look reddish because Earth’s atmosphere absorbs the other colours while it bends some sunlight toward the moon. Sunlight bending through the atmosphere and absorbing other colours is also why sunsets are orange and red.
During a total lunar eclipse, the moon is shining from all the sunrises and sunsets occurring on Earth!
Why don’t we have a lunar eclipse every month?
It’s true that the moon goes around Earth every month, but it doesn’t always get in Earth’s shadow. The moon’s path around Earth is tilted compared to Earth’s orbit around the sun. The moon can be behind Earth but still get hit by light from the sun.
Because they don’t happen every month, a lunar eclipse is a special event. Unlike solar eclipses, lots of people get to see each lunar eclipse.
Remembering the Difference
It’s easy to get these two types of eclipses mixed up. An easy way to remember the difference is in the name. The name tells you what gets darker when the eclipse happens. In a solar eclipse, the sun gets darker. In a lunar eclipse, the moon gets darker.
What are Genetically-modified Organisms (GMOs)?
Genetically-modified organisms (GMOs) can be defined as organisms (i.e. plants, animals or microorganisms) in which the genetic material (DNA) has been altered in a way that does not occur naturally by mating and/or natural recombination. The technology is often called “modern biotechnology” or “gene technology”, sometimes also “recombinant DNA technology” or “genetic engineering”. It allows selected individual genes to be transferred from one organism into another, also between nonrelated species. Foods produced from or using GM organisms are often referred to as GM foods.
GM foods are developed – and marketed – because there is some perceived advantage either to the producer or consumer of these foods.
GM crops give an increased level of crop protection through the introduction of resistance against plant diseases caused by insects or viruses or through increased tolerance towards herbicides.
Resistance against insects is achieved by incorporating into the food plant the gene for toxin production from the bacterium Bacillus thuringiensis (Bt). This toxin is currently used as a conventional insecticide in agriculture and is safe for human consumption.
Issues of concern
1. Capability of the GMOs to escape and potentially introduce the engineered genes into wild populations;
2. Persistence of the gene after the GMOs have been harvested;
3. Susceptibility of non-target organisms (e.g. insects which are not pests) to the gene product;
4. Stability of the gene;
5. Reduction in the spectrum of other plants including loss of biodiversity; and
6. Increased use of chemicals in agriculture.