The concept of a portable, inexpensive and semi-automated biosensing platform, or lab-on-a-chip, is a vision shared by many researchers and venture industries. Under this scope, we have investigated the application of optical emission from quantum well (QW) microstructures for monitoring surface phenomena on gold layers remaining in proximity (<300 nm) with QW microstructures. The uncollimated ...

We use scanning tunneling microscopy and spectroscopy to measure the energy shift of empty quantum-well (QW) states in Pb islands on the Cu(111) surface. It is found that, with an increase of the electric field, the behavior of the energy shift can be grouped into two different modes for most QW states. In the first mode, the state energy moves toward high energy monotonically. In the second mo...

We show here that the spectrum of the family of noncommutative harmonic oscillators Qw(α,β)(x,D) for α, β ∈ R+ in the range αβ = 1, is [0,+∞) and is entirely essential spectrum. The previous existing results concern the case αβ > 1 (case in which Qw(α,β)(x,D) is globally elliptic with a discrete spectrum whose qualitative properties are being extensively studied), and ours therefore extends the...

Lead quantum wells (QW) epitaxially grown on annealed Pb/Si(111) interface form a model system for the study of interactions between quantized electrons and adiabatically modulated boundaries. Tunnel spectra of this system reveal a previously unknown adiabatic shift of QW resonances due to lateral variations of the electronic reflection phase at the buried interface. With this effect, lateral d...

We report on the mechanism of strain-influenced quantum well (QW) thickness reduction in GaN/AlN short-period superlattices grown by plasma-assisted molecular beam epitaxy. Density functional theory was used to support the idea of a thermally activated exchange mechanism between Al adatoms and Ga surface atoms that is influenced by the strain state of the GaN QWs. These ab initio calculations s...

GaAsSb/GaAs quantum well QW lasers grown by solid source molecular beam epitaxy are fabricated into ridge lasers and tested. These devices have a lasing wavelength around 1.2 m that is substantially blueshifted relative to the electroluminescence peak. The magnitude of the blueshift increases as the cavity length is shortened, indicating that the blueshift increases with injection level. This b...

Noise characteristics and resistance of semimetal-type mercury-cadmium-telluride quantum wells (QWs) at the liquid nitrogen temperature are studied numerically, and their dependence on the QW parameters and on the electron concentration is established. The QW band structure calculations are based on the full 8-band k.p Hamiltonian. The electron mobility is simulated by the direct iterative solu...

Health technology A programme of financial incentives to promote smoking cessation was examined. The programme, the "Quit and Win" (QW) contest offered a chance to win a cash prize (usually $1,000) for successfully stopping smoking for at least 1 month. The current study reported on 11 QW contests that were carried out in different communities across New York State between 2001 and 2004. In the...

Most high γ-aminobutyric acid (GABA) producers are Lactobacillus brevis of plant origin, which may be not able to ferment milk well due to its poor proteolytic nature as evidenced by the absence of genes encoding extracellular proteinases in its genome. In the present study, two glutamic acid decarboxylase (GAD) genes, gadA and gadB, were found in high GABA-producing L. brevis NPS-QW-145. Co-cu...

We consider an special dynamics of a quantum walk (QW) on a line. Initially, the walker localized at the origin of the line with arbitrary chirality, evolves to an asymptotic stationary state. In this stationary state a measurement is performed and the state resulting from this measurement is used to start a second QW evolution to achieve a second asymptotic stationary state. In previous works,...