We report the observation of narrower structures in the yellow luminescence of bulk and thin-film n-type GaN, using the technique of selective excitation. These fine structures exhibit thermal quenching associated with an activated behavior. We attribute these fine structures to phonons and electronic excitations of a shallow donor-deep acceptor complex, and determine its activation energy for ...

In this chapter the fundamental aspects involved in biological treatment processes applied for the removal of nitrogen from wastewaters are described. A comprehensive review of the literature is provided including kinetic, microbiological and biochemical aspects of nitrification, denitrification and anammox, as well as key operational parameters affecting the processes. This information is rele...

Growing public awareness of the use of donor insemination (DI) to enable infertile couples to become parents has been accompanied by increasing concern regarding the potentially negative consequences for family relationships and child development. Findings are presented from a prospective study of the quality of parenting and psychological adjustment of DI children at age 12. Thirty-seven DI fa...

BACKGROUND The Hb levels of prospective blood donors are usually determined using a finger prick test. A new noninvasive Hb device has the advantage of not causing any sampling pain. The purpose of this study was to evaluate the accuracy of the noninvasive Hb sensor and to compare its measurements with those of a currently used portable hemoglobinometer. METHODS Hb was measured using a noninv...

There is a substantial literature suggesting that computer-assisted interviewing has advantages over face-to-face and written self-administration of interviews in venues eliciting sensitive information similar to that sought in blood donor history screening. We review some of the recent developments in blood donor history screening, the evidence suggesting that automated interviews should be us...

In this paper, I present the discussive adaptive logic DLI. As is the case for other discussive logics, the intended application context of DLI is the interpretation of discussions. What is new about the system is that it does not lead to explosion when some of the premises are selfcontradictory. It is argued that this is important in view of the fact that human reasoners are not logically omni...

It is now just over three years since it became apparent that blood and blood product therapy carried with them the risk of infecting recipients with the then unknown causative agent of acquired immunodeficiency syndrome (AIDS). It was not long before the general public became aware of the risk of this possible means of transmission of the disease. Apprehension grew with the realization that ef...

in this paper, the electronic eigenstates and energy spectra of single and two-interacting electrons confined in a concentric double quantum rings with a perpendicular magnetic field in the presence of         on-center donor and acceptor impurities are calculated using the exact diagonalization method. for a single electron case, the binding energy of on-center donor and acceptor impurities ar...