Science & Technology Current Affairs - 2019
Science & Technology Current Affairs 2019-2020 category comprises current affairs with all important national / international updates in science and tech and events for the year 2019-2020 for UPSC, States, Civil services, SSC and other competitive examinations of India and States.
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A team from Indian Institute of Technology (IIT) Hyderabad has developed a Dye-Sensitised Solar Cell (DSSC) which is based on New Fuchsin (NF) dye with aqueous electrolyte and platinum-free counter electrodes. The research was published in Solar Energy journal.
Need: Currently, most familiar solar cells today are made up of Silicon (Si) and can be seen in various overhead panels and other places. However, this technology is limited by huge fabrication costs as Si processing is very expensive and involves very high temperature methods that leave a large carbon footprint. Therefore to get around limitations of using Si, IIT Hyderabad team started working on solar cells based on organic materials for photovoltaic technology, which were supposedly inexpensive and easy to fabricate.
Initially, after facing many drawbacks IIT Hyderabad along with other researchers employed a very cheap magenta-dye called New Fuchsin, which is used to make kumkum or vermillion when grounded with turmeric. New Fuchsin is an inexpensive dye available off-shelf in most supermarkets in India, and in its purest form costs $2 per gramme.
About Dye-Sensitised Solar Cell (DSSC)
It is a 3rd-generation thin-film organic Molecule-Based Energy Conversion Device.
DSSC is cheap, non-toxic and is soluble in water and does not degrade in presence of water. It takes inspiration from nature, almost mimicking primary process of photosynthesis phenomenon in plants.
DSSC has 3 components:
- Monolayer of dye molecule adsorbed on semiconductor material
- Titanium dioxide (TiO2) deposited on transparent conductive oxides, like indium tin oxide (ITO)
- Liquid electrolyte with an excess of electrons
Process involved: Sunlight is absorbed by dye molecule and gets excited. Electrons from excited dye molecule get injected into conduction band of TiO2 and then electrons are transported to charge collector. Dye cation (after losing its electron) takes an electron from surrounding electron-rich liquid electrolyte. The counter electrode, typically, is platinum-coated ITO.
DSSCs are generally considered eco-friendlier to produce than conventional solar cells because they require little energy to manufacture.
Drawbacks: Best performing DSSCs use organic solvent-based liquid electrolytes but these liquid-electrolytes come with drawbacks like high vapour pressure, toxicity and sometimes explosives resulting in severe environmental impact in addition to being corrosive to the platinum counter-electrodes, thereby limiting long-time stability of the devices.
To help geriatric care, students of IIT Kharagpur have developed an application called CARE4U that connect the caregiver to the elderly person. It will inform the caregiver when elderly person falls down with exact location.
It is an android-based app that will connect caregiver to elderly person. By using the network-based fall detection algorithm in CARE4U app installed on phone of elderly can detect whether elderly has fallen down.
If there is a fall, app automatically calls caregiver and emergency services along with providing exact location of elderly person.
Features of CARE4U App
Mood Index: App can also detect emotions as whenever elderly opens the app the phone takes his picture and a mood index is calculated. This index detects whether person is sad or not and automatically updates caregiver with time stamp. Thus caregiver can check what mood senior citizen has been through in day.
Cognitive Intelligent Chatbot: To make mood index feature more effective IIT team has developed a cognitive intelligent chatbot for elderly person to engage with. For instance chatbot can recommend a motivational quote or an old song when the person is sad.
No cloud service: Best thing about app is that except for chatbot, all other machine learning models run on mobile itself i.e. no cloud service is needed. This implies that even if there is no internet connection, all other features such as fall detection, emotion detection will work.
Medicine Reminder: It also has a record of medical histories, allergies’ account, an SOS (emergency) button, real time location tracking and also has Medicine Reminder feature to remind both elderly as well as caregiver that it is time for former to take medicine.