Keep it cool
Many would be aware about the blue-painted houses of the ‘sun city’ Jodhpur, also known as the blue-city for many tourists, where the day temperature is average of about 33.6°C and the record high temperature is 54°C. While on a tour to Jodhpur, we were given to understand by tourist guides that houses are painted white and blue to protect it from the sun’s heat. Travel photos from the Mediterranean and Middle East often show a landscape of homes with white roofs and walls.
Cool roof coatings
High consumption of electricity in running air conditioners / coolers in summer is a usual phenomenon. A rough estimate shows that there is a saving of Rs480 Crores per annum in electricity if the temperature of a roof-top house (size 1000 sq. ft and having a one ton AC, running only for 10 hours) is reduced by 10 o C. This in turn will reduce the carbon foot print and hence global warming.
Growth of strictly monolayer large continuous MoS 2 films on diverse substrates
Despite a tremendous interest on molybdenum disulphide as a thinnest direct band gap semiconductor with a huge potential for application in optoelectronics and plasmonics, single step synthesis of a large area purely monolayer MoS 2 film has not yet been reported. We have adopted a chemical vapour deposition (CVD) route to synthesise a continuous film of strictly monolayer MoS 2 covering an area as large as several mm 2 on a variety of different substrates without using any seeding material or any elaborate pre-treatment of the substrate.
Polycarbocyclic cage compounds as high energy density materials
Polycarbocyclic cage compounds
■ Synthesised from readily available starting materials in minimum number of steps
In comparison with conventional propellants/explosives, polycyclic cage compounds exhibit
■ High positive heat of formation (ΔH f ), high density, high angle and torsional strain
■ High specific impulse (I sp ), higher heat capacity, superior burning rate, greater heat release
■ Kinetic stability: stable to light, air and water, no spontaneous decomposition or shock sensitivity
Managing energy, computationally
Efficient use of energy is an age-old goal. But its importance has become even more apparent with the increased emphasis on human development and the increased use and thirst for more energy that it engenders.Efficient use of energy is an age-old goal. But its importance has become even more apparent with the increased emphasis on human development and the increased use and thirst for more energy that it engenders.
Our focus is on addressing energy concerns through the use of information and communication technologies:
Interested in conserving your resources! Pinch Analysis may help you
Pinch Analysis was originally developed as a thermodynamic tool to conserve thermal energy in chemical process industries through a network of heat exchangers.
Understanding the effect of external acoustic forcing on impinging jet atomisation used in liquid rocket combustors
Due to the simple design, better atomisation and mixing characteristics, the impinging jet configuration has been a preferred injection system for storable liquid propellant rocket engines. The major problem associated with liquid propellant rocket engines using the impinging jet injector configuration is combustion instability. Acoustic oscillations in the combustion chamber affects the process atomisation leading to oscillatory sheet breakup and spray formation. This further causes unsteady heat release favorable for sustaining the combustion instability.
Low-dimensional materials for energy harvesting
As we know, energy can’t be converted 100% into work. For instance, about more than a third of energy from fuel in internal combustion engine in a car goes into running the vehicle and majority of the fuel gets wasted as a heat. One can harness part of this waste heat (generated in vehicles, electronic circuits, factories as well as in natural heat sources) and turn it into useful energy, which can partly solve some of our energy problems. Thermoelectric materials converts part of the heat into useful electrical current.
Modeling of grain-oriented ferromagnetic materials in transformers
Grain-oriented (GO) materials are commonly used in magnetic circuits of power transformers. They provide a high permeable path for the main magnetic flux with minimum iron (or core) losses for magnetisation along their rolling direction (RD). These materials exhibit hysteretic, anisotropic, and dynamic features in their magnetisation process. Numerical simulations have to be carried out to optimise design, to pre-estimate the losses, and to test design performance under transient conditions.
Analysis of current interruption process in vacuum circuit breakers
Vacuum circuit breakers (VCBs) are finding increased usage in the medium voltage range (1 - 52 kV) due to their robustness and compactness. As the entire current interruption process takes place inside a closed vacuum enclosure (vacuum bottle), the VCB is maintenance free. Vacuum technology has progressed over the years and VCBs have become increasingly compact. As a result they have developed an edge over SF6 circuit breakers. Presently, VCBs have a comparable market share as that of SF6 breakers in the switchgear sector.