Week 34 Flashcards
What is Magnetar?
A magnetar is an exotic type ofneutron star, its defining feature that it has an ultra-powerfulmagnetic field.
The field is about 1,000 times stronger than a normal neutron star and about atrilliontimes stronger than the Earth’s.
Apart from ultra-powerful magnetic fields, magnetars also release vast amounts of energy in the form of flares,X-rays, andgamma-ray bursts.
They are therefore associated with extreme events in the universe, making them perhaps the most bizarre objects in the cosmos next toblack holes.
The magnetic field of a magnetar may be caused by a neutron star’s interior – thought to be made up of neutrons, quarks and exotic states of matter such asBose-Einstein Condensates– becoming asuperconducting fluid.
Thus, when the star rotates, it would behave like a hugedynamo, generating an immense magnetic field.
What is a Supernova?
A supernova is the name given to thecataclysmic explosion of a massive star.
They are thelargest explosion that takes place in space.
A star can go supernova in one of two ways:
Type I supernova:Star accumulates matter from a nearbyneighbouruntil arunaway nuclear reaction ignites.
Type II supernova:Star runs out of nuclear fueland collapses under its own gravity.
It canemit more energy in a few seconds than our sun will radiate in its lifetimeof billions of years.
They’re also theprimary source of heavy elements in the universe.
On average, a supernova will occur once every 50 yearsin a galaxy the size of theMilky Way.
What are Wolf-Rayet stars?
These are massive stars that are near the end of their stellar evolution.
They are typically more than 25 times the mass the Sun and lose this mass at a very high rate.
They are a rare sight and are among the most luminous, most massive, and most briefly-detectable stars known to scientists.
Green Hydrogen Standard
The Ministry of New & Renewable Energy has decided to define Green Hydrogen as having a well-to-gate emission (i.e., including water treatment, electrolysis, gas purification, drying and compression of hydrogen) of not more than 2 kg CO2equivalent / kg H2.
The Bureau of Energy Efficiency (BEE), Ministry of Power shall be the Nodal Authority for accreditation of agencies for the monitoring, verification and certification for Green Hydrogen production projects.
The scope of the definition encompasses both electrolysis-based and biomass-based hydrogen production methods.
What is Green Hydrogen?
Hydrogen gas(produced using industrial methods like electrolysis) can be used as a fuel and it does not release greenhouse gas (GHG) emissions such as carbon dioxide (CO2) when it is burned. Hence,a potential clean alternativeto fossil fuels.
Green hydrogenis the name given tohydrogen gas that has been produced using renewable energy, such as wind or solar power, which create no GHG emissions.
Globally, most of the hydrogen produced today is used in therefining and industrial sectors- to make ammonia for the fertiliser industry, in the steel industry.
In a fuel cell(device that converts the energy of a chemical into electricity),hydrogen gas reacts with oxygen to produce electricityand water vapour.
Sapphire
The name SAPPHIRE is derived from the Latin word ‘Saphirus’ and the Greek word ‘Sapherios’ both the words mean blue.
The scientific name of sapphire is called corundum. It is made up of aluminium oxide (Al203) mineral.
Corundum comes in all types of colours like red, pink, yellow, orange and violet.
Distribution:
Sapphire is found all over the world. Sri Lanka is still a top source for natural sapphire.
In India the reserves/resources of corundum are found in association with kyanite and sillimanite in Assam, Meghalaya and Maharashtra.
It occurs in syenites and ultrabasic rocks inTelangana.
The total reserves/resources of sapphire was estimated at 450 kg, all of which is placed under ‘Remaining Resources’ category and is located in Jammu & Kashmir.
Uses:
Sapphire has emerged as a versatile material useful to a range of industries in many varied applications including LEDs, optical and Radio Frequency Integrated Circuits (RFICS).
Why isKashmirsapphirefamous?
Kashmirsapphiresare valued as significantly as they are because they contain only the best specimens.
These specimens are noted to have a superior cornflower blue tint with a sleepy quality to them.
Indira Gandhi Memorial Tulip Garden
Indira Gandhi Memorial Tulip Garden, previouslyModel Floriculture Centre, is atulipgarden inSrinagar, Jammu and Kashmir.
It is the largesttulipgarden inAsia,spread over an area of about 30 hectares.
It is situated on the foothills ofthe Zabarwan Rangewith an overview ofDal Lake.
The garden was opened in 2007 with the aim to boost floriculture and tourism inKashmir Valley.
The garden is built on a sloping ground in a terraced fashion consisting of seven terraces.
The garden houses about 48 varieties of tulip flowers. The garden also has several types of other flowers, including daffodils, hyacinths, roses, narcissus, and other ornamental plants.
The Indira Gandhi Memorial Tulip Garden in Srinagar recently entered the World Book of Records (London) as Asia’s largest such park.
Tulip festival:
Itis an annual celebration that aims to showcase the range of flowers in the garden as a part of tourism efforts by the Government of Jammu and Kashmir.
It is organized during the onset of the spring season in Kashmir valley.
Acoustic Side Channel Attack
Thistechniqueuses the sounds produced bytyping on a keyboardto determine what keys are being pressed.
By analysing theseunique sounds,hackers equipped with the right tools can decode the precise letters and numbers being typed.
Researchers investigated the use of audio recordings taken from Zoom video conferencing calls, smartphone microphones, and off-the-shelf equipment and algorithms to launch ASCA attacks.
The study found that when trained on keystrokes by a nearby phone, the classifier achieved an accuracy of 95%, the highest accuracy seen without the use of a language model.
Accuracy
When a deep learning model was trained on the data with default values, the model was able to acquire a meaningful interpretation of the data.
On a MacBook Pro, which features a keyboard identical in switch design to Apple’s models from the last two years, the model was able to achieve state-of-the-art accuracy with minimal training data.
Additionally, when the AI model was made to recognise keystrokes using audio captured through a smartphone microphone, it was able to achieve 95% accuracy.
Implications
This form of hacking could expose sensitive information like passwords and personal messages.
