A novel route to achieve 2D carrier confinement in a wedge shaped wall structure made of a polar semiconductor has been demonstrated. Our theory reveals that the wedge shape leads to the development of charges of equal polarity on the two inclined facades of the wall. Polarisation induced negative (positive) charges on the facades can push the electrons (holes) inward for a n-type (p-type) material which results in the formation of a 2D electron (hole) gas at the central plane and ionised donors (acceptors) at the outer edges of the wall.

Modern gun-battles are rarely waged on open ground where enemies face each other, and the origin of unfriendly and friendly fire are easy to locate. Instead, most combats are now staged in obstacle-dense situations like cities, forests and mountain valleys, where the location of a shooter may be difficult to pinpoint aurally due to reverberations. More importantly, our security forces may not even be present within audible range of all gunshots at all times, due to the highly mobile nature of modern combat.

Composites have been extensively used in the manufacturing of wind turbine blades over the past two decades. Significant expertise and field experience has been accumulated in the design, manufacturing and repair / maintenance of these wind turbine blades. However, with the increasing blade length, the design imperatives have pushed the materials used for the blade construction from conventional E-glass to carbon fiber based polymer composites. This shift also leads to design shift from stiffness limited design to strength limited design.

Particle image velocimetry (PIV) technique is used for measurement of fluid velocity. It involves seeding micron-size particles in a flow, illuminating the particles with a laser pulse, capturing the position of the particles using a camera, and finally interrogating two such time elapsed images to obtain the displacement (and velocity) of the particle (or flow). The technique provides information at numerous points simultaneously and is non-intrusive; these advantages make PIV score substantially higher than conventional techniques (such as Pitot tube).

In current scenario, environmental pollution has become a greater challenge for the whole mankind. Main source of the pollutant includes industrial applications, air and land based traffic. These emissions are mainly CO, NO x and UHC (unburned hydro carbon) causing many harmful effects like acid rain, smog and haze resulting in global warming. It is expected that emissions norms will become stricter in near future. It is reported that by 2025, NO x , CO and UHC should be reduced by 80%.

Combustion driven power sources offer astounding advantages over conventional chemical batteries, such as higher energy densities, lower weight, short recharging time, limitless number of rechargeable cycles and environment friendly operation. These devices have wide applications in micro satellite thrusters, MEMS, chemical sensing,and micro air vehicles (MAV).

The cleaner and higher efficiency burning of syngas mixtures in integrated gasification combined cycle (IGCC) have made syngas the most promising alternative to conventional fossil fuels for power generation. The burning velocity is an intrinsic property of a combustible mixture that characterises the overall reaction rate of the flame. We determined the laminar burning velocities of multi-component mixtures experimentally at elevated temperatures. The combustion characteristics of practical syngas mixtures is vital for efficient use of lean premixed mode of syngas-air mixtures in IGCC.

Identification of small-scale combustion based devices as high energy density source and development of modern microfabrication techniques has led to many opportunities in the area of development of micro-power generation devices. These combustion based micro power devices are expected to feed the portable micromechanical, communication, sensing biomedical systems, UAVs, micro-thrusters and various micro-scale industrial applications.

The interest of the automotive and aviation community in biofuels has surged in the past decade primarily due to a shift in global awareness towards cutting greenhouse gas emissions. This has translated into stringent policies for fuel usage and emission norms. In this context, the research community has shifted its focus towards biofuels as a part of the larger renewable plan for the planet.

TMT (Thirty Meter Telescope) is one of the world’s largest ground based telescope project. The telescope’s primary mirror is 30 meters in diameter and is comprised of hundreds of hexagonal mirror segments. Each mirror segment is mounted on a critical support component known as the central diaphragm.

Precision machining is perhaps one of the most essential and widely performed manufacturing processes in several industries today, particularly in the aerospace and automotive sectors. It is amongst the few conventional manufacturing processes which ensure that raw materials are converted efficiently into functional components within the tolerance limits set by design. This is crucial in order to ensure optimal system performance.

The Avionics equipments are integrated on various aircrafts using mounting trays. Modern day aircrafts are designed with avionics bays where the avionics equipments are mounted. The mounting tray is an interface between the avionic equipment and the aircraft frame.

These mounting trays should withstand all the dynamic loading conditions like random vibration, Sine on random vibration, gun fire vibration, shock & arrestor landing shock, etc. depending on the aircraft requirements.

Product development activities in the 21 st century face several challenges such as shorter product life cycles, frequent design revisions and need for shortest time to market. Globalisation has added a new dimension to this scenario forcing manufacturers to look for solutions to automate and integrate product life cycle activities. Internet has emerged an excellent tool providing interoperability among designers, manufacturers, suppliers and end users for distributed global product development.

Melting and freezing phenomena are inherent to several important cross disciplinary applications such as manufacturing of cast products, welding and other fusion processing, polymer processing, food processing, and geophysical systems. These are typically multi-scale and multi-phase in nature. The final product such as an automobile piston or an ice-cream, is a result of a controlled processing of a multi-component material in liquid or semi-solid state.

The pulverised coal combustion in a swirl burner is a complex phenomenon. A simplified numerical model, using RANS approach, has been developed in order to predict the combustion processes in a swirl burner with an accuracy comparable to that of Large Eddy Simulations (LES). The effect of different combustion environments such as air, oxy-steam (O 2 /H 2 O) and oxy-recycled flue gas (O 2 /CO 2 ) on gas temperature and NO concentration has been studied.

Combustion in a conventional spark ignition engine is initiated by a spark. High temperature zone of initially spherical shape is created by the spark and it grows to consume turbulent premixed fuel-air mixture in the combustion chamber.In direct numerical simulation (DNS) all the length and time scales are resolved. DNS of growth of a flame kernel in a turbulent premixed medium provides fundamental insights into the interaction of flame kernel with turbulence.

A full anechoic chamber has recently been installed in the Aerodynamics Laboratory of the Department of Aerospace Engineering. All four inside walls including ceiling and floor are fitted with sound absorbing non-reflecting wedges which provide ambience with lower cut-off frequency of 200 Hz.

This all steel suction type wind tunnel is housed in the Department of Aerospace Engineering and has many unique features. For example, it has high aspect ratio honeycomb constructed out of thin acrylic sheet and 5 very fine stainless steel screens in the settling chamber followed by a 9 to 1 contraction for excellent quality flow with good uniformity and low turbulence level in the test section measuring 3’ x 3’ in cross section and 8’ in length. With these not so big dimensions this wind tunnel happens to be the largest size wind tunnel in the state of Maharashtra.

Missile based electronic warfare involve a number of techniques, like remote eves dropping, signal jamming and decoy signal generation. For decoy applications, dummy missile has receivers working over a very wide bandwidth that can sense the incoming signals from the enemy missile, and then play it back. The key requirement is that the antenna for such decoy systems must be able to receive and transmit simultaneously, over a very large bandwidth. Secondly the incoming wave can be both left hand circular polarised (LHCP) and right hand circular polarised (RHCP).

Directed energy systems (DES) are a class of systems used for various purposes like Electronic warfare, remote mine clearing and testing the vulnerability of electronic systems under Electromagnetic radiation. They have several advantages over conventional weapon systems like limited debris or garbage production and also they are affected less by rain or fog. For DES, a high power source like virtual cathode oscillator (vircator) or relativistic magnetron is used. These sources have the capability to produce power in the range of Gigawatts.