a chromium electroplating bath with the ability to produce homogenous mist was used to evaluate parameters influencing hexavalent chromium (cr+6) mist sampling methods. the results of 48 cr+6mist samples collected using the u.s. national institute for occupational safety and health method 7600showed that cr+6concentration was higher: (1) for sampling by closed-face filter cassettes than for sam...

We present an alternative method for measuring ultrashort extreme-ultraviolet pulses that can be synchronized with an intense infrared pulse. The method, based on photoionization of a target atom by the extremeultraviolet pulse in the presence of the infrared pulse, has a potential accuracy of close to 1 fs and is susceptible to single-shot operation. It is demonstrated on harmonic 15 of a tita...

We present a monolithic passively Q-switched microchip laser generating 200 ps pulses at a wavelength of 1064 nm with a repetition rate of up to 2 MHz. While maintaining transversal and longitudinal single-mode operation, the pulse energy can be changed from 130 nJ to 400 nJ by varying the pump conditions of the laser. To the best of our knowledge, the repetition rate of 2 MHz is by far the hig...

In this paper we show that every real-time system speciied in a certain subset of Duration Calculus 24] can be decomposed into an untimed system communicating with suitable timers. Both asynchronous and synchronous communication are considered.

The spin dynamics in Ni is studied by an exact diagonalization method on the ultrafast time scale. It is shown that the femtosecond relaxation of the magneto-optical response results from exchange interaction and spin-orbit coupling. Each of the two mechanisms affects the relaxation process differently. We find that the intrinsic spin dynamics occurs during about 10 fs while extrinsic effects s...

We present a complete axiomatisation of the operator of projection onto state in the Duration Calculus (DC ) relative to validity in DC without extending constructs. Projection onto state was introduced and studied extensively in our earlier works. We first establish the completeness of a system of axioms and proof rules for the operator relative to validity in the extension of DC by neighbourh...

Among the possible approaches for expressing real-time problems with the B method, two are dominant : the use of the usual B mechanisms to define temporal constraints on one hand, and extending B through another formalism more adapted to the real-time context. We define here a possible temporal semantic for B, by using a temporal logic (the duration calculus), and we illustrate how this extensi...

in order to evaluate the impact of different amounts of nitrogen fertilizer on growth and yield of two forage sorghum cultivars, a 2-year field experiment was carried out at the college of agriculture, shiraz university, shiraz, iran during 2010 and 2011 growing seasons. two factorial experiments were carried out in randomized block design with three replicates, in which the treatments included...

We present a spatial and temporal logic based on Duration Calculus for the specification and verification of mobile real-time systems. We demonstrate the use of the formalism and apply it to a case study. We extend a pure Duration Calculus specification for the controller by spatial assumptions to reason about spatial system properties. We prove that the formalism is undecidable in general for ...

In this paper we present the main achievements of UNU/IIST during the project “Design Techniques for Real-time Systems” carried out since 1993 by its staff and fellows. Duration Calculus was originally introduced in 1991 as a powerful logic for specifying the safety of realtime systems. During the project, it has evolved to a set of calculi that can capture many important aspects in real-time s...