We report the capacitive spring softening effect observed in single-walled carbon nanotube (SWNT) nanoelectromechanical (NEM) resonators. The nanotube resonators adopt a dual-gate configuration with both bottom-gate and end-gate capable of tuning the resonance frequency through capacitive coupling. Interestingly, downward resonance frequency shifting is observed with increasing end-gate voltage...

Fresh-cut banana slices have a short shelf-life due to fast browning and softening after processing. The effects of atmospheric modification, exposure to 1-MCP, and chemical dips on the quality of fresh-cut bananas were determined. Low levels of O2 (2 and 4 kPa) and high levels of CO2 (5 and 10 kPa), alone or in combination, did not prevent browning and softening of fresh-cut banana slices. Sof...

For metals it is widely accepted that the stress-strain diagram is symmetric with regard to tension and compression when plotted in terms of true rather than nominal quantities. Kinematic considerations state that the engineering definition of nominal strain exhibits fundamental deficiencies under rigid body rotations and deformations which are not truly infinitesimal. For these two reasons the...

The rocks are formed through very complex processes and the complex behaviour of rock masses is dominated by the planes of weaknesses . Rock mass consists of intact rock and discontinuities. Many rocks show strain softening behaviour under loads. In this paper, the constitutive models for intact rocks and rock joints are presented. These form the basis for the development of constitutive models...

Softening frequently occurs in dual-phase steels under isothermal tempering of martensite. Recently, non-isothermal tempering is implemented to decrease the softening process in dualphase steels. Here, we have discovered using high power electropulsing treatment can significantly enhance the strengthening effects via the formation of ultrafine-grained ferrite with nano-cementite particles in te...

Recent Bauschinger-type tests conducted on a twinning-induced plasticity (TWIP) steel highlights the important contribution of internal stresses to work hardening [1]. Along this line we present Bauschinger experiments in a Fe-22Mn wt.%-0.6C wt.% TWIP steel. The mechanical behaviour upon load reversal shows transient and permanent softening effects. Determination of the internal stress from the...

The large strain nonlinear stress-strain behavior of thermoplastic polyurethanes (TPUs) exhibits strong hysteresis, rate dependence and softening. Thermoplastic polyurethanes are copolymers composed of hard and soft segments. The hard and soft segments phase separate to form a microstructure of hard and soft domains typically on a length scale of a few tens of nanometers. Studies have revealed ...

T he first programmable computers were rather nasty beasts. These giant 1940s machines occupied entire rooms and consumed kilowatts of electricity. The computation problems engineers faced more often involved failed machine hardware components than the short and mostly unchanging programs engineers fed to those machines. Engineers viewed computers and their programs as unified entities. Over th...

The softening of fleshy fruits, such as tomato (Solanum lycopersicum), during ripening is generally reported to result principally from disassembly of the primary cell wall and middle lamella. However, unsuccessful attempts to prolong fruit firmness by suppressing the expression of a range of wall-modifying proteins in transgenic tomato fruits do not support such a simple model. 'Delayed Fruit ...