A simple formal semantics for the standard hardware description language vhdl is set out in functional style. The presentation comprises an executable speci-cation for a synchronously clocked vhdl simulator.

There is possibility of microbial contamination of any single-dose vials (SDVs), multiple-dose vials (MDVs) and admixtures (ADXs) during the preparation and injection to the patients that could be resulted in bloodstream infection. The goal of this study was to investigate the microbial contamination of MDVs and SDVs after multiple use and ADXs prepared by nursing staff in the treatment room ve...

This article describes CLEAN, an approach to the detection of low-energy solar neutrinos and neutrinos released from supernovae. The CLEAN concept is based on the detection of elastic scattering events (neutrino-electron scattering and neutrinonuclear scattering) in liquified noble gases such as liquid helium, liquid neon, and liquid xenon, all of which scintillate brightly in the ultraviolet. ...

Let A be a finite alphabet and let DcA * be a finite set of words to be labelled "dirty". Let {Xa: a E A} be commuting indeterminates. To every letter a E A we assign the weight Xa and the weight of a word is the product of the weights of its letters. For example, weight (13221) = X1X3X2X2X1 = XiX~X3. Given any set S of words we let weight (S) be the sum of the weights of the members of S. For ...

Unprecedented industrial development during the last two decades, accompanied by a growing population, has increased the amount of environmental damage in Indonesia. A critical environmental problem is the rising level of air pollution in several large cities. This has stimulated the government to develop a national program designed to control the quantity of pollutants in the air. However, the...

We introduce the notion of clean ideal, which is a natural generalization of clean rings. It is shown that every matrix ideal over a clean ideal of a ring is clean. Also we prove that every ideal having stable range one of a regular ring is clean. These generalize the corresponding results for clean rings. 1. Introduction. Let R be a unital ring. We say that R is a clean ring in case every elem...

A ring with identity is said to be clean if every element can be written as a sum of a unit and an idempotent. The study of clean rings has been at the forefront of ring theory over the past decade. The theory of partially-ordered groups has a nice and long history and since there are several ways of relating a ring to a (unital) partially-ordered group it became apparent that there ought to be...

The Einstein Cross, Q 2237+0305, has been photometrically observed in four bands on two successive nights at NOT (La Palma, Spain) in October 1995. Three independent algorithms have been used to analyse the data: an automatic image decomposition technique, a CLEAN algorithm and the new MCS deconvolution code. The photometric and astrometric results obtained with the three methods are presented....

Sir,?In the course of my holiday rambles in the North, I have come across dirty cows being milked in the dirtiest possible surroundings. I cannot too strongly express my horror to think that milk, probably to be seen, a few hours later, in brightly burnished churns on white tiles in some spotless city dairy shop, is being produced under unspeakably filthy conditions. I need not go into details ...

Fuel cells are receiving widespread attention as an alternate source for clean energy, and one of the most important developments are proton-exchange membrane fuel cells (PEMFC) which operate using hydrogen at low temperatures. In the U.S., there is a considerable effort underway to develop H2 as the preferred fuel due to the potential for decreasing our dependence on imported oil, and the envi...