Long-term series

Reusable in a long-term series of batch reactions or continuously in flow systems. 

This book explicitly supports an open data policy for the Baltic Sea region, in particular by its Digital Supplement CD with a large number of key parameters provided as long-term series, together with reference data, such as shorelines, bottom topography, or the equations... 

Without the pretence of being complete or representative, in Section 5.2 we report a number of typical mean seasonal cycles. They should suffice for certain basic estimates, but must be rendered more precisely for detailed studies. Typical averaging periods are the past 50 or 100 years, but this depends on the availability of the particular data. Since the water residence time of the entire Baltic region is about 30 years, climatic considerations should preferably be based on long-term series exceeding this internal timescale. In Section 5.3, we briefly consider certain trends observed in these data sets. Local trends may be different in summer or winter due to the seasonally different weather regimes over the Baltic Sea. 

In order to better understand the ice regime in the Baltic Sea and its changes in the past, present and future, it has been found practical not to analyze every single ice winter of the long-term series but to study classes of ice winters having similar characteristics. Some methods used to classify the ice winters in the different parts of the Baltic Sea are described below. 

Even with the restriction of content mentioned above it is impossible to collect the literature exhaustively. To overcome this problem, some recent reviews related to application of various in situ techniques are cited instead of numerous original papers. Publications of active research groups woilcing systematically in the field are cited selectively (if these studies present a long-term series, typically the latest papers are mentioned). Citations of rarely available papers are more sizeable (still not exhaustive), to avoid a loss of original sources. Illustrations attempt to present some less known data in a compact form. 

The Kl-method suffers from several interferences, particularly by sulfur dioxide (SO2). Ozone measurements by the Kl-method from urban sites must be regarded with some caution because sulfur dioxide is a major air pollutant produced by the combustion of fossil fuels (e g., of coal). At some stations a C1O3 filter was introduced to remove the bias of SO2, causing possible problems in the homogeneity of the long-term series. Measurements of rural and Alpine sites are much less influenced by such problems. Because of these interferences present monitoring measurements are usnaUy based on the UV-method (see earlier). 

F or NjO, estimates of soil emissions are perhaps slightly more straightforward, simply because so much more information on soil NjO emissions is available. For agricultural soils, estimates as a percentage of fertilizer input have been published " and, for the remaining land use classes listed in Table 5, mean annual emissions from a series of long-term flux measurements are available. The total annual soil NjO emissions for the ElK (27 kt N) are very similar to the annual soil NO emissions. Soils, however, have by far a greater impact on the... 

H type columns must be used at a flow rate and pressure drop below maximum values listed in Tables 4.12-4.16. Standard flow rates are also listed in these tables. They are flow rate range recommendable for long-term usage in tetrahydrofuran at 25°C and vary with temperature. H type columns can be operated at a higher flow rate at elevated temperatures. They also vary with solvent depending on the viscosity. They are approximately inversely proportional to the solvent viscosity. The maximum pressure drop listed in the tables is for one column. When some columns are used in series, the total maximum pressure drop is a summation of values of all columns. 

However, while transition-metal ions often contain unpaired electrons, they exhibit none of the reactivity that is commonly associated with such radicals outside the d block. There is no behaviour comparable to that of the highly reactive and short lived radicals such as CH3. Also associated with the presence of unpaired electrons in these species is the phenomenon of paramagnetism. The long-term stability of many compounds with unpaired electrons is a characteristic of the transition-metal series. 

Marenco, A., Gouget H., Nedelec P., Pages, J.-P. and Karcher, F. (1994). Evidence of a long-term trend in tropospheric ozone from Pic du Midi data series consequences positive radiative forcing. /. Geophys. Res. 99,16617-16632. 

Considering the high hydrophobicity of the palmitoyl side chain and the rigidity of the polymer backbone, we assumed that poly(N-palmitoylhydroxyproline ester) would degrade somewhat more slowly than poly (lactic acid) or polycaprolactone. In order to confirm this hypothesis, a series of long-term stability and degradation studies have been performed over the last 2 years at MIT (22). 

A series of soil microcosms were used to study the biodegradation and bioavailability of pyrene during long-term incubation. The nonextractable fraction of -labeled pyrene that had been introduced into pristine soil and incubated with or without the addition of azide was substantially greater in the latter (Guthrie and Pfaender 1998). It was also shown that microbial activity produced a number of unidentified polar metabolites that might plausibly be involved in the association. 

Finally, the value of extensive time-series records extends beyond the identification of a specific problem. Long-term time-series permits verification that decisions are effective (or not) solutions are, indeed, working (or not) and the ongoing costs and benefits of the given control program are assessed accurately. With proper design of what to measure, it can also assist in understanding the why or why not. 

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