We study heat transport in semiconductor nanostructures by solving the Boltzmann Transport Equation by means of the Discrete Ordinate Method. Relaxation time and phase and group velocity spectral dependencies are taken into account. The Holland model of phonon relaxation time is revisited and recalculated from dispersion relations in order to match bulk silicon and germanium [...]
A nonlinear differential equation about optimal shapes for blades of a fan. A boundary value differential problem from engineering, geometrical or physical bonds. A relation between linear profiles and constant speed along the side under flow. [arXiv.org, 26 Mar 2008] Read more
We study the important problem of tracking moving targets in wireless sensor networks. We try to overcome the limitations of standard state of the art tracking methods based on continuous location tracking, i.e. the high energy dissipation and communication overhead imposed by the active participation of sensors in the tracking process and the low scalability, [...]
Role-playing and debates are examples of innovative techniques that engineering faculty — often working with professional writing instructors — are using to sharpen student writing abilities. Educators argue that the best way to hone students’ writing skills is to insert more writing instruction into engineering curricula. “If engineering students only rely on freshman English classes, [...]
Wally Wallington has demonstrated that he can lift a Stonehenge-sized pillar weighing 22,000 lbs and moved a barn over 300 ft. What makes this so special is that he does it using only himself, gravity, and his incredible ingenuity. Forgotten Technology
Electrons in atoms possess both spin and orbital degrees of freedom. In non-relativistic quantum mechanics, these are independent, resulting in large degeneracies in atomic spectra. However, relativistic effects couple the spin and orbital motion, leading to the well-known fine structure in their spectra. The electronic states in defect-free carbon nanotubes are widely believed to be [...]
One of the most pervasive problems afflicting people throughout the world is inadequate access to clean water and sanitation. Problems with water are expected to grow worse in the coming decades, with water scarcity occurring globally, even in regions currently considered water-rich. Addressing these problems calls out for a tremendous amount of research to be [...]
The X Prize Foundation, best known for its competitions promoting space flights, is offering $10 million to the teams that can produce the most production-ready vehicles that get 100 miles per gallon or more. More than 60 teams from nine countries have signed up for the competition so far, including California electric carmakers Aptera Motors [...]
The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak [...]
The goal of the electronics program is to develop and transition affordable, high performance Radio Frequency (RF) electronics that will provide a decisive edge to the warfighter. The program encompasses RF research, design, modeling, fabrication, and testing of devices, integrated circuits, and multi-chip assemblies that span digital, analog, microwave and millimeter wave technologies. Read [...]