Science and Technology

Piezoelectricity

What is Piezoelectricity?

• The Piezoelectric Effect: Ability of certain materials to generate electric charge under mechanical stress.
• Discovered in 1880 by Pierre and Paul-Jacques Curie.

Piezoelectric Principle

• Caused by the unusual crystal structures of some materials.
• Application of stress creates asymmetry in charges, generating a small electric current.
• Some materials exhibit the inverse effect (electric current causing mechanical deformation).

Applications

• Direct Piezoelectric Effect:
  • Pressure sensors
  • Accelerometers
  • Acoustic devices (microphones, phonograph pickups)
• Inverse Piezoelectric Effect:
  • Wave filters in telephones

Polity

Curative Petition

Concept

• Introduced by the Supreme Court in Rupa Ashok Hurra vs Ashok Hurra and Anr (2002).
• Last resort to seek justice from the Supreme Court for a perceived wrong in its decision.
• Not prescribed in the Constitution.

Process

• Only after a review plea dismissal by the Supreme Court.
• Circulated to a bench of three senior-most judges (including judges from the original case, if available).
• If a majority agrees, the petition is sent to the original bench (if possible).

Health

Methanol

Context

• US hand sanitizer recall due to toxic methanol content (health risks like nausea, coma, even death).

About Methanol

• Simplest alcohol (CH3OH), also known as methyl alcohol.
• Chemical building block in various products (plastics, paints, car parts, construction materials).
• Clean energy resource (fuels cars, trucks, etc.).

Health Risks

• Nausea, vomiting, headache, blurred vision
• Coma, seizures, permanent blindness
• Permanent damage to central nervous system
• Death