Investigations of the emissions of monoterpenes from Scots Pine

Plants produce and emit a large number of volatile organic compounds (VOC) such as isoprene and monoterpenes (C10H16). Monoterpene emission rates from Scots pine (Pinus sylvestris), a typical central European conifer, were measured under ambient conditions within the scope of this work. The studies focused on diurnal and seasonal cycles of monoterpene emissions, branch-to-branch and plant-to-plant variability of emission rates, and on the transferability ofresults from laboratory (studies of Dr. J. Wildt and coworkers) and outdoor measurements. Generally, no significant differences between the results obtained under laboratory and ambient environmental conditions were found. Under both laboratory and ambient conditions, monoterpene emissions were found to increase with needle temperature at a rate of 5 % to 16 % per Kelvin and fonowed under otherwise unchanged conditions an Arrhenius type dependence on temperature. The temperature dependence of emissions was without a clear seasonal trend and without significant differences from plant-to-plant. Only in the laboratory a dependence of emission rates on photosynthetic active radiation (PAR) was found (increase of 20-30% at a constant temperature, saturation in the light dependence at about 15 % of fun sunlight). Under outdoor conditions, a PAR dependence was not detected. Seasonal variations of a single branch and branch-to-branch variations in the spectrum of emitted monoterpenes were small, but different individual Scots pines emitted a completely different spectrum of monoterpenes. The temperature normalized standard emission rates were found to be highly variable. Values for the sum of monoterpenes ranged between 0.06 and 0.65 µg g(dW)-lh-1 (microgram monoterpenes per gram dry weight of needles and hour) for young pines and between 0.24 and 3.7 µg g(dW)-lh-1 for the adult pine. The variations of the standard emission rates from the same plant at different times of the year were on the same order of magnitude as the plant-to-plant variability. Stress to the plant was a possible explanation for these variations, but this effect could not be described quantitatively. ßased on the results a monoterpene flux was calculated for a forest in Southern Germany (Hartheimer Wald, near Freiburg), ranging between 54-941 ng m-2s-l at T = 30°C. Future laboratory studies should focus on stress effects and their impact on VOC emissions. The effect of stress on VOC emission rates must be quantified and included in the existing models for better predictions of emission rates and fluxes

On Conditional Decomposability

The requirement of a language to be conditionally decomposable is imposed on a specification language in the coordination supervisory control framework of discrete-event systems. In this paper, we present a polynomial-time algorithm for the verification whether a language is conditionally decomposable with respect to given alphabets. Moreover, we also present a polynomial-time algorithm to extend the common alphabet so that the language becomes conditionally decomposable. A relationship of conditional decomposability to nonblockingness of modular discrete-event systems is also discussed in this paper in the general settings. It is shown that conditional decomposability is a weaker condition than nonblockingness.Comment: A few minor correction

Criteria of morphometric analysis of a daily load profile

Analysis of electrical loads is crucial for a proper operation and control of electrical energy sources and planning and design of electrical power systems in terms of optimum capacity of the electricity generation. A typical daily load profile significantly varies over the 24‐hour day and requires levelling actions which can be advised from the detailed analysis of the profile. This paper discusses the principles and implementation of morphometric analysis for a daily load profile evaluation using three criteria: roundness, compactness, and elongation. In order to conduct the morphometric analysis, the daily load profile represented as a time series has to be converted into a polygon of a particular form in a radar chart. The criteria for the profile analysis are based on geometrical interpretation of the shape of the polygon. The criterion roundness assesses the maximum and minimum loads of the profile and are related to the ratio of the inner circle of the polygon to the outer circle. The criterion compactness is based on the polygon perimeter and its inner area. The criterion elongation is defined as a relationship between the length of perpendicular to main axis of the polygon and the length of the main axis. The examples of the load profiles represented as a regular polygon and the case study have been used to demonstrate implementation of the analysis using the roundness, compactness, and elongation. It has been shown that the analysis using the morphometric criteria can be effectively applied for the detailed assessment of the load profiles