Broadband metrological-grade frequency comb (FC) synthesizers with a rich number of phase locked modes are the ideal sources for quantum sensing and metrology. At terahertz (THz) frequencies, electrically pumped cascade lasers (QCLs) have shown quantum-limited noise operation, phase/frequency absolute referencing self-starting FC albeit over rather restricted dynamic range, governed by nature g...

Background: This retrospective study aimed to investigate the physicochemical properties of drinking water sources in Ethiopia and compare the water quality with the health-based target. For this purpose, the water quality database of Ethiopian Public Health Institute (EPHI) from 2010 to 2016 was used. Methods: The concentration and other properties of the water samples were analyzed according...

Ontologies are helpful in giving interoperable structures to sources of knowledge and information. This interoperability, however, is greatly hindered by the heterogeneity of independently developed ontologies which in turn increases the requirements for mediation systems to reconcile the differences. A core concepts ontology for a certain domain contained by a foundation ontology can be used t...

The number of information sources in the Web is growing day by day with a tremendous speed. At the same time, users tend to manage more and more tasks electronically, thereby using publicly available information sources. Since the Web is an open, distributed and dynamic environment, in which information sources are offered and controlled autonomously and independently, the interoperability of a...

At least three proposed future colliders (ILC, CLiC and LHeC) require a positron source with a yield greater than 10 e+s−1. An undulator-based positron source has the potential to provide the required yield. This design generates gamma rays by using a high energy electron beam traveling through a superconducting helical undulator. The gamma rays then pair produce in a titanium alloy target to p...