619 Electrotherapy for pain has been used since 2751 BC (Kellaway, 1946) but entered modern use in 1919 with the introduction of the Electreat (Shealy, 1974). Working with this device in 1966, I asked engineers to create a similar modern solid-state unit. Initially reluctant, engineers created the first solid-state stimulator for pain control in 1971, the Stim-Tech® and shortly thereafter the N...

Molecular order has proven to be a significant factor in the performance of devices based on organic semiconductors. Recent studies involving solubilized versus unsubstituted thiophene oligomers have demonstrated that modifications which increase orbital overlap in the solid state can improve device performance by more than an order of magnitude.1 Similar studies on pentacene, a compound which ...

π-conjugated macromolecules for organic polymeric solar cells can be rationally engineered at the molecular level in order to tune the optical, electrochemical and solid-state morphology characteristics, and thus to address requirements for the efficient solid state device implementation. The synthetic accessibility of monomers and polymers required for the device is getting increasing attentio...

We review the current state of membrane protein structure determination using solid-state nuclear magnetic resonance (NMR) spectroscopy. Multidimensional magic-angle-spinning correlation NMR combined with oriented-sample experiments has made it possible to measure a full panel of structural constraints of membrane proteins directly in lipid bilayers. These constraints include torsion angles, in...

Fault current limiters are essential devices used to protect the power system and its equipment against high levels of fault current, which growing up due increase new sources. This paper proposes a novel design Hybrid Superconducting Current Limiter (Hybrid SFCL), is composed basically by thyristors in series with superconducting element. branch connected parallel an air-core reactor, improves...

background bleaching of traumatized discolored teeth is considered an important issue in esthetic dentistry. various methods have been introduced for bleaching, some of which may have adverse effects on soft or hard tissues of the tooth. objectives the objective of the study was to evaluate the effects of ktp laser bleaching on enamel of traumatized teeth. materials and methods a square of 36 m...