Showing posts with label Sciene&Technology. Show all posts

Sunday, 25 December 2016

Topic- Scramjet Engine

Scramjet Engine

Background

Oxygen is as essential for the process of combustion as it is for the sustenance of life. Therefore a rocket, during its launch, needs to combine a combustion fuel with liquid oxygen to create the thrust needed for the take-off and flight.
However, if the need for liquid oxygen is taken away (by producing air-breathing technology), the spacecraft can be much lighter, hence cheaper to launch.
While conventional rocket engines need to carry both fuel and oxidizer on board for combustion to produce thrust, air-breathing rocket systems, on the other hand, uses the atmospheric oxygen from their surroundings and burn it with the stored on- board fuel.

 Ramjet, Scramjet and Dual Mode Ramjet (DMRJ) are the three concepts of air breathing engines which are being developed by various space agencies.

 A ramjet is a form of air-breathing jet engine that uses the vehicle’s forward motion to compress incoming air for combustion without a rotating compressor.

 Ramjets work most efficiently at supersonic speeds around Mach 3 (three times the speed of sound) and can operate up to speeds of Mach 6. However, the ramjet efficiency starts to drop when the vehicle reaches hypersonic speeds.

 A dual mode ramjet (DMRJ) is a type of jet engine where a ramjet transforms into scramjet over Mach 4-8 range, which means it can efficiently operate both in subsonic and Supersonic combustor modes.

Scramjet engine

A scramjet engine is an improvement over the ramjet engine as it efficiently operates at hypersonic speeds and allows supersonic combustion. Thus it is known as Supersonic Combustion Ramjet, or Scramjet.

Scramjet engines obtain oxygen from the atmosphere by compressing the incoming air before combustion at hypersonic speed. It uses hydrogen as fuel and the oxygen from the atmospheric air as the oxidizer.

When the rocket reaches a height of 11 km, the scramjet engines would start breathing air directly from the atmosphere.

Scramjets are highly inefficient at low speeds. Their efficiency increases at supersonic speeds.

Significance

1. The spacecraft can be smaller or carry more payloads, making it a commercially viable option.

Scramjet technology effectively cuts down the cost of launching rockets by reducing its weight by more than half.

The engine, when fully developed, will eventually be used in Reusable Launch Vehicles or RLV’s.

India has become the fourth country to successfully test the scramjet engine after United States, Russia and the European Space Agency. ISRO carried out successful testing of scramjet engine from the Satish Dhawan Space Centre, Sriharikota. ISRO’s Advanced Technology Vehicle (ATV), which is an advanced sounding rocket, was the solid rocket booster used for this recent test of Scramjet engines at supersonic conditions. The space agency’s ATV rocket was able to fly at Mach 6 (six times the speed of sound) speeds.

Topic- ICANN and the Future of Internet

Background:

Before the establishment of ICANN, the function of administering registries of Internet protocol identifiers (including the distributing top-level domains and IP addresses) was performed by Jon Postel, a Computer Science researcher in USA.
As the Internet grew and expanded globally, the U.S. Department of Commerce initiated a process to establish a new organization to perform the IANA functions. Hence, ICANN came into being.

Internet Corporation for Assigned Names and Numbers (ICANN):

ICANN is a non-profit body that administrates domain names and Internet protocol addresses (IPs) globally. It was formed in 1988 by US department of commerce. It has become independent of US control since October 1st, 2016.

What does ICANN do?

To reach another person on the Internet you have to type an address into your computer – a name or a number. That address has to be unique so computers know where to find each other.
ICANN coordinates these unique identifiers across the world. Without that coordination we wouldn’t have one global Internet.

It promotes competition and develops policy on the Internet’s unique identifiers.

What ICANN doesn’t do?

ICANN through its coordination role of the Internet’s naming system has had an important impact on the expansion and evolution of the Internet. It does not engage in following tasks,

Content on the internet:ICANN is not in the business of monitoring and regulating child pornography, hate speech, scams, spoofs or other illegal material. Laws in international organizations, or in countries, states or localities, govern such activity.
Internet access: That is provided by Internet Service Providers (ISPs) that are not under the control of ICANN.
Bad actors on the internet: ICANN is not a policing enterprise. It does not investigate hackers or spammers or those accused of trademark violations.

What does ICANN have to do with IP addresses?

ICANN plays a similar administrative role with the IP addresses used by computers.
ICANN does not run the system, but it does help co-ordinate how IP addresses are supplied to avoid repetition or clashes.

ICANN is also the central repository for IP addresses, from which ranges are supplied to regional registries who in turn distribute them to network providers

The issue:

Before ICANN, Jon Postel was in charge of the Internet Assigned Numbers Authority (IANA).
Administration of the IANA was contracted to the newly-formed ICANN, but the U.S.’s National Telecommunications and Information Administration (NTIA) kept its final say over what it was able to do.
It is that final detail that is set to change from October 1. US will no longer be able to intervene on matters around internet naming(Domain Name System). No longer will the US government, through the NTIA be able to intervene on matters around internet naming.

Problem with US control:

US government could unilaterally interfere with the ICANN’spolicy process, and the Internet’s root server.
The S. President has various kinds of emergency powersregarding key infrastructure, which is likely to extend to ICANN and the root server.
The Office of Foreign Assets Control has seized foreign assets in the U.S. on the baseless geopolitical grounds. A country’s domain name (e.g. “.in”) in the root server can be considered that country’s asset inside the U.S.
Federal Communications Commission has recently declared Internet service as a public utility. It might at will seek jurisdiction over ICANN-managed critical Internet resources.
Interference from judiciary – Some adult content companies have legally challenged the ICANN-mandated .xxx domain name. A U.S. court has taken the case on file, thus exercising its jurisdiction over an ICANN policy decision.
Lastly, the U.S. legislature can make any kind of law affecting any aspect of ICANN and the root server.

India’s Position on Internet governance:

India’s proposal is that the Internet should be managed through the multi-stakeholder approach. And a pivotal role for governments as the custodian of cyberspace in the wake of security threats from terror groups.
India has described the role of the government as “an important stakeholder” and “a custodian of security” for the global Internet infrastructure.
India’s stand it that the body managing the Internet should have “accountability towards governments” in areas where “governments have primary responsibility, such as security and similar public policy concerns”.

Analysis:

It marks a transition from an internet effectively governed by one nation to a multi-stakeholder governed internet: a properly global solution for what has become a global asset.
Vested interests might take over – It is feared that the concerned industry’s narrow interests will entirely take over, with no restraints. The U.S. government at least had no reason to work for these interests.
- A few years back, it rapped ICANN when it allowed .com owners to steeply raise domain name price, and got it reversed.
The real problem of the U.S.’s executive, legislative and judicial control over ICANN and the root server will not change with the current proposal.
- What is required is to get ICANN incorporated under international law, with host country communities for an international organization.

Tuesday, 22 November 2016

Topic- Light Fidelity or Li-Fi

Light Fidelity or Li-Fi

What is Li-Fi?

Li–Fi is a Visible Light Communications system running wireless communications, traveling at very high speeds.

How does it work?

1. Li–Fi uses common household LED light bulbs to enable data transfer, reaching speeds of up to 224 gigabits per second.
2. Although Li-Fi bulbs would have to be kept on to transmit data, the bulbs could be dimmed to the point that they are not visible to humans and yet still functional.

How is it different from Wi-Fi?

1. Li-Fi and Wi-Fi are quite similar as both transmit data electromagnetically. However, Wi-Fi uses radio waves while Li-Fi runs on visible light.
2. Li-Fi signals cannot pass through walls. Therefore, it is useful for short-range transmission only.
3. Due to its shorter range, Li-Fi is more secure than Wi-Fi and it’s reported that embedded light beams reflected off a surface could still achieve 70 megabits per second.

Usage/Benefits of Li-Fi:

Freeing up the spectrum: When the traffic is diverted to Li-Fi (wherever available), already clogged cellular networks would be relieved of their burden.
Li-Fi can be used in electromagnetic sensitive areas like in aircraft cabins, hospitals, laboratories etc, without causing electromagnetic interference.
Smart lighting: Street lamps could be used to provide Li-Fi hotspots.
Electronic devices such as laptops, smart phones, tablets and other devices can interconnect directly using Li-Fi.
Transportation: Headlights and tail lights in vehicles are moving to LED and so are streetlights. Li-Fi can be used for vehicle to vehicle and vehicle to roadside communications for road safety and traffic management.
Li-Fi can also easily work underwater, where Wi-Fi fails completely, thereby throwing open endless opportunities for military and navigational operations.
Li-Fi with its impressive high speed could make a huge impact on the internet of things, with data transferred at much higher levels with even more devices able to connect to one another.
When developed fully, Li-Fi offers potential applications for a greener and cleaner future,
riding on the rapid growth in the in the use of LED across the world.

Challenges/Disadvantages:

Light cannot pass through walls so Li-Fi would have mobility issues.
To make a Li-Fi network functional throughout the house, one will need these light bulbs in every room to have seamless connectivity.
The external lights (sunlight and other bulbs) may cause obstructions in Li-Fi’s transmission.
path, thus it may create disturbances in the communication process.
Initial installation cost is high as Li-Fi receiving devices will require adapters to transmit data back to the transmitter.
One of the drawbacks is that the light needs to be on all the time to deliver connectivity.
Another drawback is that Li-Fi is not very effective outdoors, meaning that public Li-Fi will not be able to replace public Wi-Fi networks anytime soon.

Conclusion:

If Li-Fi can be put into practical use, every LED lamp (indoor as well as outdoor) can be converted into something like a hot spot to transmit data to every mobile device to achieve universal broadband communication between devices.
Also, it presents another unique possibility: transmitting power wirelessly, wherein the Smartphone will not only receive data through Li-Fi but will also receive power to charge itself. Thus, it has immense potential which can be channelized for the more inclusive and better use of the internet.

Topic- Zika Virus – All you need to know

Zika virus

Introduction

Zika virus disease is caused by a virus transmitted by Aedes mosquitoes. It is an emerging mosquito-borne virus that was first identified in Uganda in 1947 in rhesus monkeys. Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.

Symptoms

Symptoms of Zika virus infections are similar to other arbovirus infections such as dengue. Like:-

• Fever
• Skin rashes
• Conjunctivitis
• Muscle and joint pain
• Malaise, and headache

National health authorities in Brazil have reported potential neurological and auto-immune complications of Zika virus disease. Agencies investigating the Zika outbreaks are finding an increasing body of evidence about the link between Zika virus and microcephaly.

Transmission

Zika virus is transmitted to people through the bite of an infected mosquito from the Aedes genus.
This is the same mosquito that transmits dengue, chikungunya, and yellow fever.
Zika virus can migrate between humans through sexual contact
it can also cross the placenta, affecting an unborn fetus
An infected mother can pass on the virus to her newborn around the time of birth.
The vertebrate hosts of the virus are primarily monkeys and humans.

Threat

Zika virus outbreak in Latin America could be a bigger threat to global health than the Ebola epidemic.
There is currently no vaccine available for this disease.
Most virus carriers of Zika virus are symptomless.
It is a silent infection in a group of highly vulnerable individuals – pregnant women.
However, Zika virus infection during pregnancy can cause a serious birth defect.

Microcephaly– abnormal smallness of the head,a congenital condition associated with incomplete brain development called microcephaly, as well as other severe fetal brain defects.

With at least 80% of those infected showing no symptoms, tracking the disease is extremely difficult.
Only extreme measures like DDT are likely to contain the Zika threat, which will be environmentally harmful.

Prevention

Prevention and control rely on reducing mosquitoes through source reduction.
Reducing contact between mosquitoes and people.
This can be done by using insect repellent; wearing clothes (preferably light-colored).
Using physical barriers such as screens, closed doors and windows, and sleeping under mosquito nets.
Special attention and help should be given to those who may not be able to protect themselves adequately.
Zika virus is diagnosed through PCR (polymerase chain reaction) and virus isolation from blood samples.

How does virus attack?

Viruses are tiny organisms that may lead to mild to severe illnesses in humans, animals, and plants.
Viruses by themselves are not alive. They cannot grow or multiply on their own and need to enter a human or animal cell and take over the cell to help them multiply.
Viruses lie around our environment all of the time just waiting for a host cell to come along. They can enter us through the nose, mouth or breaks in the skin.
Once inside, they find a host cell to infect.
For example, cold and flu viruses will attack cells that line the respiratory or digestive tracts.
It then begins making copies of the viral genetic instructions and new viral proteins using the virus’s genetic instructions and the cells enzyme machinery.
The new copies of the viral genetic instructions are packaged inside the new protein coats to make new viruses.

Regardless of the type of host cell, all viruses follow the same basic steps:-

A virus particle attaches to a host cell.
The particle releases its genetic instructions into the host cell.
The injected genetic material recruits the host cell’s enzymes.
The enzymes make parts for more new virus particles.
The new particles assemble the parts into new viruses.
The new particles break free from the host cell Once inside the cell, the viral enzymes take over those enzymes of the host cell.

Topic- Augmented Reality

Augmented Reality

What is Augmented Reality?

Augmented reality is the integration of digital information with the user’s environment in real time. Unlike virtual reality, which creates a totally artificial environment, augmented reality uses the existing environment and overlays new information on top of it.

Applications of Augmented Reality:

1. Navigation: Enhanced GPS systems are using augmented reality to make it easier to get from point A to point B. Using the phone’s camera in combination with the GPS, the users see the selected route over the live view of what is in front of the car.
2. Sightseeing: Using a smartphone equipped with a camera, tourists can walk through historic sites and see facts and figures presented as an overlay on their live screen.
a. These applications use GPS and image recognition technology to look up data from an online
database.
b. In addition to information about a historic site, applications exist that look back in history and show how, the location looked 10, 50 or even 100 years ago.
3. Military: The Heads-Up Display (HUD) is the typical example of augmented reality when it comes to military applications of the technology.
a. A transparent display is positioned directly in the fighter pilots view. Data typically displayed to the pilot includes altitude, airspeed, and the horizon line in addition to other critical data.
b. The term “heads-up” comes from the fact that the pilot doesn’t have to look down at the aircraft’s instrumentation to get the data they need.
c. The Head-Mounted Display (HMD) is used by ground troops. Critical data such as enemy location can be presented to the soldier within their line of sight.
d. This (HMD) technology is also used for simulations for training purposes.
4. Medical: Medical students use the technology to practice surgery in a controlled environment. Also, Visualizations (with AR) aid in explaining complex medical conditions to patients. Augmented reality can reduce the risk of an operation by giving the surgeon improved sensory perception.
5. Gaming: It has changed the gaming experience in a revolutionary way. The mixing up of virtual life with real life using GPS has given a unique experience in gaming.
6. Safety and rescue operations: In the case of emergencies, the police or firefighters often arrive at chaotic scenes and need to make sense of the environment and navigate a place they have never been to. With the use of AR technology (virtual maps and X-ray vision) they can help better in such situations.

Limitations/Challenges:

1. Currently, AR works better in static, unchanging situations, and when it has to show information that is constantly changing, it becomes less accurate.
2. It has privacy concerns due to its facial and location recognition technologies.
3. With the already isolation of individuals due to various technologies (e.g. social media), AR can further lead to social detachment among people.

Recent concern related to augmented reality games:

1. Some of the games like Pokemon Go, and other advanced AR devices like Google Glass and Holo Lens are present in the market today.
2. All AR devices whether it is a game or device, distracts people from their surroundings, leading to potentially severe consequences.
3. Several countries have issued advisories regarding the game and some have even raised ‘national security’ concerns. A Pokemon Go player was robbed at knife point in New Hampshire, a player got stuck in a tree in a cemetery in New Jersey, a teenager was led to a dead body in a river in Wyoming, and in Baltimore, a man drove into a police car while chasing Pokemon.

Safety concerns Linked to children:

1. Real-world game-play has been linked to armed robberies as criminals have used the game to locate and lure intended targets and children are most vulnerable in that scenario.
2. Since these games encourage players to go to areas which may not belong to them. Trespassers whether the children or a mature person face a real threat of physical harm from property owners who may use force to protect their property.
3. The game requires users’ full attention immediately. Children playing games on the roads can meet an accident due to speedy cars or any other cause.
4. Since the game, developed by Niantic, uses Google Maps and has access to IP addresses of the users, it can be used to trace locations, in which case children are the most vulnerable and will be unable to respond to any criminal activities.
5. When a player downloads Pokémon Go, the app gets “full access” to the person’s phone. Children playing games on their parent’scellphones could give up personal data in the phones.
6. A number of doctors and psychologists feel that these games add to the stress levels of the player and children tend to get more stressed due to their immature emotional level.
7. These games can affect a growing child’s ability to distinguish between real and virtual objects.

Way ahead:

Accidents and mishaps can be avoided by being more alert and avoiding seedy locations. The guardian of children needs to be more aware as these technologies can lead to the isolation of children from family.
The only way to resolve this from the developer’s side would be to maintain a global, up-to-date information bank on what areas are off limits, and alter the gaming experience accordingly. The sheer scale of this task makes it very difficult to accomplish by today’s standards.

Saturday, 27 August 2016

Hindu(Science&Technology)- 22nd Aug 2016

Sunday, 21 August 2016

Radio Frequency Identification ( RFID)

RFID

Radio Frequency Identification (RFID) uses radio waves to communicate between two objects: a reader and a tag. RFID communication is the same as two way radio communication in the sense that information is transmitted or received via a radio wave at a specific frequency.

Passive tags collect energy from a nearby RFID reader's interrogating radio waves. Active tags have a local power source such as a battery and may operate at hundreds of meters from the RFID reader.

Emerging RFID applications include:

• Self-checkins at Libraries / rental services as well as retail premises.

• Livestock Management and pet identification.

• Toll/road – collection/charging and control measures. Many more RFID-based payment collection systems.

• Building Security - secure access controls, documentation and passports.

• Airports - for baggage tracking and tracing/locating.

• SMART home controls - systems to manage home/business energy consumption/production.

• Seismic Sensing - such as locating gas lines and temperature sensing (geophysical).

• Environmental - Energy, Ozone & Pollution measuring equipment.

Source:: Iasscore

Thursday, 14 July 2016

Biomass Energy

• Biomass, a renewable energy source, is biological material derived from living, or recently living organisms, such as wood, waste, and alcohol fuels.

• Biomass is commonly plant matter grown to generate electricity or produce, heat. For example, forest residues (such as dead trees branches and tree stumps), clippings and wood chips may lie used as biomass.

• Biomass also includes plant or animal matter used for production of fibers or chemicals: Biomass may also include biodegradable wastes that ' burnt as fuel. It excludes organic material such as fossil fuel which has been transformed by geological processes into substances such as coal or petroleum.

• Industrial biomass can 'be grown from numerous types of plant, including miscanthus, switchgrass. Hemp, corn, poplar, willow, sorghum, sugarcane, and a variety or tree species, ranging from eucalyptus palm (palm oil).

• Although fossil fuels have their origin in ancient biomass, they are not considered biomass by the generally accepted definition because they contain carbon that has been "out" of the carbon cycle fora very long time. Their combustion therefore disturbs the carbon dioxide content in the atmosphere.

Biomass Sources

• Biomass energy is derived from three distinct energy sources : wood, waste, and alcohol fuels.

1) Wood energy is derived both froth direct use of harvested wood as a fuel and from Wood waste streams. The largest source of energy from wood is pulping liquor or "black liquor", a waste product from processes of the pulp, paper and paperboard industry.

2) Waste energy is the second largest source of biomass energy. The main contributors of waste energy are municipal solid waste (MSW), manufacturing waste, and landfill gas.

3) Biomass alcohol fuel, or ethanol, is derived almost exclusively from corn. Its principal use it as an oxygenate in gasoline. For biomass fuels, the most common feedstocks used today are corn grain (for ethanol) and soybeans (for biodiesel).

Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and bio-diesel. Methane gas is the main ingredient of natural gas. Smelly stuff, like rotting garbage, and agricultural and human waste, release methane gas also called "landfill gas" or "bio-gas".

Biomass to liquids (BTLs):- Crops like corn and sugar cane can be fermented to produce the transportation fuel, ethanol. Bio-diesel, another transportation fuel, can be produced from left-aver food products like vegetable oils and animal fats. Also, Biomass to liquids (BTLs) and cellulosic ethanol are still under research. In China, more than 8 million bio-gas digesters convert manure and other organic wastes into methane. In rural India also, bio-gas plants are a popular source of energy.

How is biomass converted into energy?

1) Burning: Burning stuff like wood, waste and other plant matter releases stored chemical energy in the form of heat, which can be used to turn shafts to produce electricity. Let's see this simple illustration of how biomass is used to generate electricity.

2) Decomposition:

Things that can rot, like garbage, human and animal waste, dead animals and the like can be left to rot, releasing a gas called biogas (also known as methane gas or landfill gas). Methane can be captured by a machine called Microturbine and converted into electricity. Sometimes, animal waste (poop) can also be converted into methane by a machine called 'Anaerobic Digester'

3) Fermentation:

Ethanol can be produced from crops with lots of sugars, like corn and sugarcane. The process used to produce ethanol is called gasification.

Biorefinery :- develop technology for biorefineries that will convert biomass into a range of valuable fuels, chemicals, materials, and products—much like oil refineries and petrochemical plants do.

Advanced technologies for the biomass energy applications:

• Biofuels — Converting biomass into liquid fuels for transportation

• Biopower — Burning biomass directly, or converting it into gaseous or liquid fuels that burn more efficiently, to generate electricity

• Bioproducts — Converting biomass into chemicals for making plastics and other products that typically are made from petroleum.

Benefits of Biomass Energy:-

1) No Harmful Emissions:- Biomass energy, for the most part, creates no harmful carbon dioxide emissions.

2) Clean Energy: It does release carbon dioxide but captures carbon dioxide for its own growth.

3) Abundant and Renewable: Since they come from living sources, and life is cyclical, these products potentially never run out, so long as there is something living on earth and there is someone there to turn that living things components and waste products into energy.

4) Reduce Dependency on Fossil Fuels: It has developed as an alternate source of fuel for many homeowners and have helped them to reduce their dependency on fossil fuels.

5) Reduce Landfills: Another benefit of this energy is that it can take waste that is harmful to the environment and turn it into something useful. For instance, garbage as landfill can, at least partially, be burned to create useable biomass energy.

6) Can be Used to Create Different Products: Biomass energy is also versatile, as different forms of organic matter can be used to create different products. Ethanol and similar fuels can be made from corn and other crops. With so many living things on the planet, there is no limit to how many ways it can be found and used.

Disadvantages of Biomass Energy:-

1) Expensive: Firstly, its expensive. Living things are expensive to care for, feed, and house, and all of that has to be considered when trying to use waste products from animals for fuel.

2) Inefficient as Compared to Fossil Fuels: Ethanol, as a biodiesel is terribly inefficient when compared to gasoline.

3) Harmful to Environment: Using animal and human waste to power engines may save on carbon dioxide emissions, but it increases methane gases, which are also harmful to the Earth’s ozone layer.

4) Consume More Fuel: Using trees and tree products to power machines is inefficient as well.

5) Require More Land: Combustion of biomass products require some land where they can easily be burnt.

Biomass Energy in India

About 32% of the total primary energy use in the country is still derived from biomass and more than 70% of the country’s population depends upon it for its energy needs. The current availability of biomass in India is estimated at about 500 millions metric tones per year. India has over 5,800 MW biomass based power plants comprising 4,760 MW grid connected and 927 MW off-grid power plants.

Bottlenecks faced by the Indian Biomass Industry

1) Lack of adequate policy framework and effective financing mechanisms

2) Lack of effective regulatory framework

3) Lack of technical capacity

4) Absence of effective information dissemination

5) Limited successful commercial demonstration model experience

Government incentives and Subsidies for Biomass Energy Production

• The Ministry of New and Renewable Energy (MNRE) provides Central Financial Assistance (CFA) in the form of capital subsidy and financial incentives to the biomass energy projects in India.

• Biomass Energy for Rural India (BERI) Project sponsored by GEF-UNDP, ICEF. The Project aims at developing and implementing a bio-energy technology package to reduce Green House Gas (GHG) emissions and to promote a sustainable and participatory approach in meeting rural energy needs.

Source:: Iasscore

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