Piezoelectric loudspeaker is characterized by its very simple constructions, but their radiation performance at low frequency region is poor because their conventional diaphragm is too stiff for large amplitude vibration. This paper proposes three innovative methods for improvement of low frequency radiation performance of piezoelectric direct-radiator loudspeakers by new constructions and mate...

We present a noncontact method for quantitative composition and thickness monitoring of flat sheet products using terahertz time-domain spectroscopy. We apply the method to obtain simultaneous measurement of thickness and moisture content of paper sheets. The paper is modeled as an effective medium of water mixed with fibers, and model parameters are estimated from fits to the measured transmis...

The interaction between elasticity and capillarity is used to produce three-dimensional structures through the wrapping of a liquid droplet by a planar sheet. The final encapsulated 3D shape is controlled by tailoring the initial geometry of the flat membrane. Balancing interfacial energy with elastic bending energy provides a critical length scale below which encapsulation cannot occur, which ...

A decision support system to reduce energy consumption has been validated during five months in a flat sheet membrane bioreactor pilot plant treating urban wastewater. Membrane bioreactor technology consists of biological nutrient removal combined with physical separation using microfiltration or ultrafiltration membranes for wastewater treatment. The main operational cost in membrane bioreacto...

Optical reflectivity and transmission measurements over photon energies between 0.2 and 1.2 eV were performed on single-crystal graphene samples on a SiO2 substrate. For photon energies above 0.5 eV, graphene yielded a spectrally flat optical absorbance of (2.3+/-0.2)%. This result is in agreement with a constant absorbance of pialpha, or a sheet conductivity of pie2/2h, predicted within a mode...

We study wrappings of the unit sphere by a piece of paper (or, perhaps more accurately, a piece of foil). Such wrappings differ from standard origami because they require infinitely many infinitesimally small “folds” in order to transform the flat sheet into a positive-curvature sphere. Our goal is to find shapes that have small area even when expanded to shapes that tile the plane. We characte...

Rolling processes for which the characteristic length scale reaches into the range where size effects become important are receiving increased interest. In particularly, this is owed to the roll-molding process under development for high-throughput of micronscale surface features. The study presented revolves around the rolling induced effect of visco-plasticity (ranging hot and cold rolling) i...

We report a nonlinear finite element analysis (FEA) of the thermo-mechanical shrinking and self-folding behavior of pre-strained polystyrene polymer sheets. Self-folding is useful for actuation, packaging, and remote deployment of flat surfaces that convert to 3D objects in response to a stimulus such as heat. The proposed FEA model accounts for the viscoelastic recovery of pre-strained polysty...

The Escherichia coli RecA protein triggers both DNA repair and mutagenesis in a process known as the SOS response. The 81-residue E. coli protein DinI inhibits activity of RecA in vivo. The solution structure of DinI has been determined by multidimensional triple resonance NMR spectroscopy, using restraints derived from two sets of residual dipolar couplings, obtained in bicelle and phage media...

Raspy crickets (Orthoptera: Gryllacrididae) are unique among the orthopterans in producing silk, which is used to build shelters. This work studied the material composition and the fabrication of cricket silk for the first time. We examined silk-webs produced in captivity, which comprised cylindrical fibers and flat films. Spectra obtained from micro-Raman experiments indicated that the silk is...