An animal bioassay has been used to evaluate a series of airborne chemicals for their sensory irritating properties to the upper respiratory tract. Teh results obtained can be used to rank their potency. An attempt has been made to predict "safe" levels of exposure for humans on the basis of this short-term assay. A good correlation was obtained between the predicted "safe" levels of exposure a...

Using a function algebra characterization of exponential time due to Monien 5], in the style of Bellantoni-Cook 2], we characterize exponential time functions of linear growth via a safe course-of-values recursion scheme.

Introduction Occupational exposure limits (OELs) 1 for the protection of workers have been around at least since 1939 when the National (later changed to American) Conference of Governmental Industrial Hygienists (ACGIH) published its inaugural acceptable workplace exposure limits (now known as threshold limit values, or TLVs). In 1970, the U. S. Occupational Safety and Health Act incorporated ...

Rising levels and spread in IDDQ values render single threshold IDDQ testing obsolete for highperformance chips for deep sub-micron technologies. Increased inter-die and intra-die variations cause unacceptable yield loss with a single pass/fail limit. Use of spatial information to estimate fault-free IDDQ is investigated. Flush delay information is used to refine this estimate under varying pro...

The phenomena of selection and coexistence are modelled as chemical pattern formation by competition for a given Ž . resource in heterogeneous spatial fields fitness landscapes . The reactions form a closed reproductive cycle so that total concentration of species and their building-blocks is kept constant in time. Eigen’s ‘constant overall organization’ conditions can be view as a particular c...