💥Mains Ready By December. Smash Mains & Smash PYQ Admissions Open
Talk to Mentor

Civilsdaily

Login

Subject: Basic Sciences

  • [pib] Energy-efficient Photodetector for Security Application

    Indian scientists have fabricated an economical and energy-efficient wafer-scale photodetector using gold – silicon interface, for security applications.

    A basic question on the working principle of Photodetectors can be asked in the Prelims.

    What are Photodetectors?

    • Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation.
    • A photodetector has a p–n (positive-negative) junction that converts light photons into the current.
    • The absorbed photons make electron-hole pairs in the depletion region.
    • Photodiodes and phototransistors are a few examples of photodetectors. Solar cells convert some of the light energy absorbed into electrical energy.
    • The material cost and the intricate fabrication processes involved in realizing high-performance detectors make them unaffordable for day to day applications.

    Applications

    • Photodetectors are the heart of any optoelectronic circuit that can detect light.
    • They are employed for a wide variety of applications ranging from controlling automatic lighting in supermarkets to detecting radiation from the outer galaxy as well as security-related applications.
    • They range from simple devices that automatically open supermarket doors, to receivers on the TV remote controls.

    What did Indian researchers achieve?

    • The scientists have fabricated gold (Au) – silicon (Si) interface, which showed high sensitivity towards light demonstrating the photodetection action.
    • The Au–Si interface was brought about by galvanic deposition, a technique for electroplating of metals, wherein water-based solutions (electrolytes) are used, which contain the metals to be deposited as ions.
    • In addition, a nanostructured Au film also was deposited on top of p-type silicide (having an excess of positive charges), which acts as a charge collector.

    Benefits

    • Being a solution-based technique, the method is highly economical and enabled large-area fabrication without compromising the detector response.
    • The process is quick, taking only minutes to fabricate a detector of any arbitrary area and exhibited a rapid response of 40 microseconds.
    • This photodetector displayed long-term environmental stability.
    • The Indian invention provides a simple and cost-effective solution-based fabrication method for high-performance photodetector.
    • It could help detect weak scattered light as an indication of unwanted activity.

  • Bay of Bengal Boundary Layer Experiment (BoBBLE)

    A team from IISc Bengaluru and UK based researchers has created a blueprint for accurate prediction of monsoon, tropical cyclones and another weather-related forecast under the BoBBLE Experiment.

    Aspirants must note:

    1) BoBBLE is headed by which organizations?

    2) Its purpose and application

    What is BoBBLE?

    • The Bay of Bengal Boundary Layer Experiment or BoBBLE in short is a project funded by Union Ministry of Earth Sciences and the Natural Environment Research Council of UK.
    • BoBBLE tries to determine, quantify and model ocean-atmosphere interactions that drive variability in the South Asian monsoon.
    • The experiment created a blueprint for future weather system observational experiments for accurately forecasting monsoon rainfall.

    Why need BoBBLE?

    • The Bay of Bengal (BoB) plays a fundamental role in controlling the weather systems that make up the South Asian summer monsoon system.
    • In particular, the southern BoB has cooler sea surface temperatures (SST) that influence ocean-atmosphere interaction and impact the monsoon.
    • Compared to the southeastern BoB, the southwestern BoB is cooler, more saline receives much less rain, and is influenced by the summer monsoon current (SMC).
    • To examine the impact of these features on the monsoon, the BoB Boundary Layer Experiment (BoBBLE) was undertaken.

    BONUS:

    1) How technology development in monsoon forecasting can benefit realizing the dream of doubling farmers income by 2022?

    2) Discuss the role of Bay of Bengal in monsoon dynamics. (Hint: the link between the two lies in Indian Ocean Dipole (IOD))

    How is the experiment carried out?

    • BoBBLE will deploy two ships, six ocean gliders and eight floats to collect an unprecedented range of oceanic and air-sea flux observations.
    • These will occupy locations in the southwest and southeast Bay, as well as tracing east-west and north-south paths between those locations, measuring ocean temperature, salinity and currents.

    With inputs from http://www.walker.ac.uk/research/projects/bay-of-bengal-boundary-layer-experiment-bobble/

  • [pib] UV Blaster: A UV Disinfection Tower

    The DRDO has developed an Ultra Violet (UV) Disinfection Tower for rapid and chemical-free disinfection of high infection-prone areas.

    GYAN:

    We have a UV filter in our home based water filter.  Ever wondered, how do UV rays kill viruses/bacteria?

    UV Blaster

    • The UV blaster is a UV based area sanitizer designed and developed by Laser Science & Technology Centre (LASTEC), the Delhi based premier laboratory of DRDO.
    • It is useful for high tech surfaces like electronic equipment, computers and other gadgets in laboratories and offices that are not suitable for disinfection with chemical methods.
    • The product is also effective for areas with a large flow of people such as airports, shopping malls, metros, hotels, factories, offices, etc.

    How does it work?

    • The UV based area sanitizer may be used by remote operation through laptop/mobile phone using wifi link.
    • The equipment has six lamps each with 43 watts of UV-C power at 254 nm wavelength for 360-degree illumination.
    • For a room of about 12 x 12 feet dimension, the disinfection time is about 10 minutes and 30 minutes for 400 square feet area by positioning the equipment at different places within the room.
    • This sanitizer switches off on the accidental opening of a room or human intervention.

    Back2Basics: UV germicidal irradiation

    • UV irradiation is a disinfection method that uses short-wavelength ultraviolet rays to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions.
    • UVGI is used in a variety of applications, such as food, air, and water purification.
    • UVGI devices can produce strong enough UVC light in circulating air or water systems to make them inhospitable environments to microorganisms such as bacteria, viruses, moulds, and other pathogens.
    • UVGI can be coupled with a filtration system to sanitize air and water.
    • It has been used primarily in medical sanitation and sterile work facilities.
    • Increasingly, it has been employed to sterilize drinking and wastewater since the holding facilities are enclosed and can be circulated to ensure a higher exposure to the UV.

  • [pib] HCARD robot to assist frontline COVID-19 healthcare warriors

    HCARD, a robot, to assist frontline COVID-19 healthcare warriors has been developed by a CSIR lab.

    It is very unlikely to create a prelim question on HCARD. However, developments as such help in exemplifying the scientific developments which helped contain such highly contagious outbreaks.

    What is HCARD?

    • The robotic device HCARD, an acronym for Hospital Care Assistive Robotic Device, can help frontline healthcare workers in maintaining physical distance from those infected by the coronavirus.
    • The device is equipped with various state-of-the-art technologies and works both in automatic as well as manual modes of navigation.
    • This robot can be controlled and monitored by a nursing booth with a control station having such features as navigation, drawer activation for providing medicines and food to patients, sample collection and audio-visual communication.
    • The cost of this device is less than Rs 5 lakh and the weight is less than 80 kilograms.

  • The Curie Family and its Nobel legacy

    This newscard is inspired by an article published in the DTE which talks about a family which has received a total of four Nobel prizes, the highest won by a single-family.

    Last year in 2019 CSP, there was a question on pure Biology about Hepatitis and its variants. With such news trending, we can expect a core chemistry or physics based question coupled with a slight Current Affairs blend.

    The ‘Nobel’ family

    • On April 20, 1902, Marie and Pierre Curie successfully isolated radioactive radium salts from pitchblende, a mineral, in a laboratory in Paris, France.
    • They were inspired by French physicist Henri Becquerel’s 1896 experiment on phosphorescence or the phenomenon that allows certain objects to glow in the dark.
    • They were able to find traces of two radioactive elements—polonium (Element 84) and radium (Element 88).
    • Curie shared the 1903 Nobel with her fellow researcher Pierre Currie and Becquerel for their combined work on radioactivity.

    Important facts

    • In 1903, Marie Curie received the Nobel Prize in Physics making her the world’s first woman to win the prize.
    • In 1911, she created history again by becoming the first woman to have won two Nobel awards.
    • The 1911 Nobel Prize in Chemistry was awarded to Marie after she managed to produce radium as a pure metal. This proved the new element’s existence beyond doubt.
    • However, this was not the last Nobel for the Curie family.
    • The 1935 Nobel in Chemistry went to Irène Curie and her husband and co-researcher Frédéric Joliot for their joint work on the artificial creation of new radioactive elements.
    • The Curies have received a total of four of Nobel prizes, the highest won by a single-family. They also have the unique distinction of having three Nobel-prize winning members in the family.

    Birth of Radioactivity

    • While delivering a lecture at the Royal Academy of Sciences in Stockholm, Sweden in 1911, Curie shared some critical details about “radioactive elements” and the phenomenon called “radioactivity”.
    • She also spoke about the chemical properties of radium, the new element that was about a million times more radioactive than uranium.
    • Radium in solid salts was about 5 million times more radioactive than an equal weight of uranium.

    Back2Basics: Radioactivity

    • Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability.
    • It is the process by which an unstable atomic nucleus loses energy by radiation.
    • The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay.
    • Radioactive decay rates are normally stated in terms of their half-lives, and the half-life of a given nuclear species is related to its radiation risk.
    • Examining the amounts of decay products makes possible radioactive dating.

    Its applications

    • Medical use: Many diseases such as cancer are cured by radiotherapy. Sterilization of medical instruments and food is another common application of radiation.
    • Scientific use: Alpha particles emitted from the radioisotopes are used for nuclear reactions.
    • Industrial use: Radioisotopes are used as fuel for atomic energy reactors. Also used in Carbon dating.

  • [pib] ‘NanoBlitz 3D’ tool to map properties of nano-materials

    Indian scientists have developed an advanced tool for mapping nano-mechanical properties of materials like multi-phase alloys, composites, and multi-layered coatings.

    Nanotechnology is a pathbreaking technology which can create many new materials and devices with a wide range of applications, such as in nanomedicine, nanoelectronics etc.  NanoBlitz 3D is another distinct development. We can expect a prelims question asking what the NanoBlitz 3D is , with confusing options like 3d printing tool etc.

     NanoBlitz 3D

    • Scientists from Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) an autonomous institute under the Dept. of S&T have developed this tool.
    • It is an advanced tool for mapping nano-mechanical properties of materials like multi-phase alloys, composites, and multi-layered coatings.
    • The tool has been useful to yield excellent results on a wide range of material systems, including glass-fibre-reinforced polymer composites, dual-phase steels, softwood and shale.
    • An important aspect of this technique is its high-throughput, with just a few hours of testing required for generating more than 10,000 data points that can be processed using machine learning (ML) algorithms.

  • [pib] Ionospheric Electron Density (IED) and its applications

    Researchers from the Indian Institute of Geomagnetism (IIG), Mumbai, have developed a global model to predict the ionospheric electron density with larger data coverage—a crucial need for communication and navigation.

    We can gauge these days that PIB is coming with ample news which is visibly important and are focused on basic GS concept. Ionospheric Electron Density is one such concept. Its significance for prelims cannot be denied.

    Ionospheric Electron Density (IED)

    • The ionosphere exists between about 90 and 1000 km above the earth’s surface.
    • Radiation from the sun ionizes atoms and molecules here, liberating electrons from molecules and creating a space of free electron and ions.

    Studying IED

    • The ionospheric variability is greatly influenced by both solar originated processes and the neutral atmosphere origin.
    • Scientists have tried to model the ionosphere using theoretical and empirical techniques; however, the accurate prediction of electron density is still a challenging task.
    • In recent years, Artificial Neural Networks (ANNs) are showing potential to handle more complex and non-linear problems.

    What are Artificial Neural Networks (ANNs)?

    • ANNs are computing systems vaguely inspired by the biological neural networks that constitute animal brains.
    • Such systems “learn” to perform tasks by considering examples, generally without being programmed with task-specific rules.
    • For example, in image recognition, they might learn to identify images that contain cats by analyzing example images that have been manually labeled as “cat” or “no cat” and using the results to identify cats in other images.
    • They do this without any prior knowledge of cats, for example, that they have fur, tails, whiskers and cat-like faces.
    • Instead, they automatically generate identifying characteristics from the examples that they process.

    Significance of IED

    • Due to the ability of ionized atmospheric gases to refract high frequency (HF, or shortwave) radio waves, the ionosphere can reflect radio waves directed into the sky back toward the Earth.
    • Radio waves directed at an angle into the sky can return to Earth beyond the horizon.
    • This technique, called “skip” or “skywave” propagation, has been used since the 1920s to communicate at international or intercontinental distances.

  • [pib] Plasmonic Semiconductor Nanomaterials

    Researchers are exploring ways to develop plasmonic semiconductor nanomaterials for removal of toxic organic compounds from water by harvesting solar light.

    Nanotechnology is a pathbreaking technology which can create many new materials and devices with a wide range of applications, such as in nanomedicine, nanoelectronics etc.  PSN is one such application. Topics like PSN are most likely to be asked in the competitive examinations.

    Plasmonic Semiconductor Nanomaterials

    • PSN are metal-like materials with free electrons on the surface that oscillate collectively when hit by light.
    • It uses solar light to increase the photocatalytic efficiency to degrade pollutants as well as generate renewable Hydrogen.
    • These materials can easily adsorb toxic ions like arsenic and fluoride, which are often found in water in North East India and convert it to its not toxic forms when they are exposed to sunlight.
    • PSN can be used for hydrogen energy generation, a process which has shown high photon to hydrogen conversion efficiency under visible and near infra-red light.

    What are Semiconductors?

    • Semiconductors are materials which have a conductivity between conductors (generally metals) and nonconductors or insulators (such as most ceramics).
    • Its resistance falls as its temperature rises; metals are the opposite.
    • They can be pure elements, such as silicon or germanium, or compounds such as gallium arsenide or cadmium selenide.

    Back2Basics: Nanomaterials

    • Nanomaterials are materials of which a single unit small-sized (in at least one dimension) between 1 and 100 nm (the usual definition of nanoscale).
    • Materials with structure at the nanoscale often have unique optical, electronic, or mechanical properties.
    • They are created from the gas phase by producing a vapour of the product material using chemical or physical means.
    • Examples of nanomaterials include carbon nanotube, nanoparticles, metal rubber, quantum dots, nanopores and many more.

  • TB diagnostic kit ‘Truenat’

    ‘Truenat’, a diagnostic machine used to test drug-resistant TB has now been approved by Indian Council of Medical Research (ICMR) for conducting Covid-19 tests.

    Truenat

    • The Truenat TB test is a new molecular test that can diagnosis TB in one hour as well as testing for resistance to the drug rifampicin.
    • This test for TB uses a sputum sample taken from each patient.
    • It is a small battery operated device which requires minimal training and is usable even in smaller settings such as the Primary Health Centre.
    • It uses a chip-based technology and takes just up to 60 minutes for a test, screening or confirmatory.

  • [pib] Chitra Acrylosorb Secretion Solidification System

    Scientists at Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) have designed and developed a highly efficient superabsorbent material for liquid respiratory and other body fluid solidification and disinfection for the safe management of infected respiratory secretions.

     Chitra Acrylosorb Secretion Solidification System

    • It is a highly efficient superabsorbent material for liquid respiratory and other body fluid solidification and disinfection.
    • AcryloSorb can absorb liquids at least 20 times more than its dry weight and also contains a decontaminant for in situ disinfection.
    • Containers filled with this material will immobilize the contaminated fluid by solidifying it (gel-like), thus avoiding spillage and will also disinfect it.
    • The canister containing the solidified waste canister can then be decomposed as all other biomedical waste by incineration.

    How it works?

    • In the developed system, suction canisters, disposable spit bags have been designed with “AcryloSorb” technology.
    • They are lined inside with the AcryloSorb material.
    • The AcryloSorb suction canisters will collect the liquid respiratory secretions from ICU patients or those with copious secretions treated in the wards.
    • The container will be spill-proof and can be sealed after use, making it safe and fit for disposal through the usual incineration system for biomedical wastes.

    Significance of Acrylosorb

    • Sealable and disposable spit bags can be provided for solidifying the sputum and saliva of ambulant patients with respiratory infections, which can then be incinerated.
    • Thus it reduces the risk for the hospital staff, the need for personnel for disinfecting and cleaning the bottles and canisters for reusing them and makes the disposal safer and easier.