Current Affairs 6th Aug 2017

 

1.  LOW –  COST  , SENSITIVE   CO   SENSOR   FROM   IISc

SOURCE- HINDU

RELEVANCE- GS MAINS -III . AWARENESS   IN   FIELD   OF   NANOTECHNOLOGY.

  • Indian Institute of Science researchers have developed a highly sensitive nanometre-scale carbon monoxide sensor by employing an innovative fabrication technique.
  • Typically, a sensor would be a thin, current carrying plate whose resistance changes on exposure to carbon monoxide. This in turn changes the value of the current flowing through it. This change when measured indicates the level of carbon monoxide in the air.
  • Most available sensors are in the micrometer range, a nanometer-sized detector would have a higher sensitivity, but the cost of manufacturing it goes up as the size decreases. This is where the work of C.S. Prajapati and coworkers of Indian Institute of Science comes in.

HOW   THE   CO   SENSOR   WAS   MADE ?

  • To build this zinc-oxide (ZnO) nanostructure on a silicon wafer substrate, the researchers first placed tiny polystyrene beads on the wafer. These beads arrange themselves into what is called a hexagonal close-packed structure on the oxidised silicon wafer.
  • Maintaining a reasonable level of vacuum, a high voltage is applied which “etches away” the surfaces of the beads until a gap of desired thickness is formed between adjacent beads. Then zinc oxide is deposited on the system.
  • This occupies the spaces between the beads, forming a honeycomb like nano-mesh that can function as a nanosenor.

ADVANTAGES   OF   THIS   DEVICE

  • Scaling down from 10 micrometer feature size to 10 nanometer feature (used in this work) can enhance the efficiency 1,000 times.
  • This device is also easy to scale for mass production.
  • Nanostructure-based gas sensors are very promising in their performance due their high surface-to-volume ratio.
  • The existing techniques to create honeycomb nanostructures using photolithography and e-beam lithography are expensive and time-consuming.
  • The proposed technique can potentially reduce the cost by more than 50%.

 

2.  IIT   DELHI   TEAM   DEVELOPS   A   NEW   ANTI – BACTERIAL   DRUG   DELIVERY   SYSTEM

SOURCE – HINDU

RELEVANCE – GS MAINS -III . AWARENESS   IN   FIELD   OF   NANOTECHNOLOGY.

  • A new antibiotic drug-delivery system that improves the efficacy of drugs thereby reducing the dosage used for treating bacterial infections has been tested in a lab by researchers at the Indian Institute of Technology (IIT) Delhi.
  • A peptide, which has not been approved for clinical use, bound to gold nanoparticles was able to kill E. coli and Salmonella typhi more efficiently at lower dosages.

WHY   NANOCONJUGATION ?

  • The peptide in a free form may not be bioavailable as it gets degraded relatively fast.
  • In a free form, the peptide is also not able to effectively kill the bacteria by engaging with the bacterial membrane and disrupting it, while the nanoconjugate fares better on these counts.
  • The peptide called sushi-peptide bound to nanoparticles was able to kill 50% of bacteria at much lower concentration (400 nM) while the free peptide’s antibacterial activity was not significant at the same concentration.

THE   CHALLENGE !

  • The challenge was to arrive at an optimum number of peptides that are bound to nanoparticles to get the best results.
  • When there are too few or too many peptides bound to the nanoparticles the antibacterial activity gets compromised.

 

3.  WOTR    BAGS   UN   AWARD   FOR   WORK   ON    LAND   DEGRADATION

SOURCE – HINDU

RELEVANCE – GS PRELIMS

  •  Watershed Organisation Trust (WOTR) has been awarded the prestigious United Nations Convention to Combat Desertification (UNCCD) ‘Land for Life Award’ for its work in some of the country’s most arid parts.
  • The recognition comes for WOTR’s programmes on sustained land management across seven states including Maharashtra and Madhya Pradesh.

BACKGROUND

  • The Union Government has set an ambitious target of doubling farm income by 2022, but this will be impossible to achieve without combating land degradation.
  • Desertification afflicts 57% land. Hence emphasis should be on to teach farmers to catch rainwater across landscapes, recharge groundwater aquifers and improvement of soil health.

LAND   FOR   LIFE   AWARD

  • The Land for Life Award was launched at the tenth session of the Conference of the Parties to the United Nations Convention to Combat Desertification (UNCCD) seeking to promote efforts for sustainable land management as part of the Changwon Initiative in 2011.
  • The Land for Life Award  provides global recognition to individuals, teams, institutions, businesses, research institutes, public offices, political leaders, decision-makers, journalists, media, nongovernmental organizations and civil society organizations whose work and initiatives have made a significant and innovative contribution to sustainable land management.
  • The Award rewards initiatives which contribute directly or indirectly to the regeneration and/or enhancement of soils’ natural health and productive capacity or to the sustainable regeneration of depleted or drought affected lands.