Issue 3

Soil-contamination from toxic explosive residues at military bases throughout the world, is a major
environmental concern. A strong candidate for TNT soil-contamination within Greece, is the military
base/airport of Maleme in Crete. While soil sampling was in progress new routes of trace analysis for
explosives in soil were explored. Solid-phase micro-extraction (SPME) was used to selectively preconcentrate
analytes prior to GC/MS. In the preliminary experiments (effectuated on water-spiked samples)
optimization of the SPME technique was achieved by controlling parameters such as sampling
method, salt content and sample agitation. As immersion of the SPME fiber was found to be more efficient
for extracting most analytes of interest, a pretreatment step was introduced for the soil samples
which simply converted them to water samples. The developed SPME protocol was able to screen
explosives in spiked-soils, in concentrations well below the certified reporting and detection limits.

Water resulting from the dewatering process of petroleum storage tanks was treated in a pilot separator
to investigate the effectiveness of the combined action of a coagulant (aluminum sulfate) and a
cationic flocculant (NALCO 71403). Central composite design of experiments was used to construct
second order response surfaces for the turbidity, suspended solids and oil content as optimization parameters.
The coagulant and flocculant concentrations and pH were used as design factors. The separator
constructed for this purpose proved to be suitable for fast and reliable investigation of multivariable
systems and for search of the optimum via statistical design of experiments.

A so called “Exact Form” of the Maximum Likelihood Method is used to obtain directional spectrum
estimates from a 3-meter NDBC discus buoy, part of the Surface Wave Dynamics Experiment
(SWADE) field array. The method was used to look at the response of wavefields to turning winds with
various wind shift gradients. For slowly turning winds, the spectrum was found to smoothly adjust to
the wind changes. As the wind shift gradient increased, a portion of the spectral energy was found to
be decoupled from the wind while the bulk of the spectrum smoothly adjusted to the new wind direction.
Finally, for even larger wind shift gradients, the preexisting spectrum was completely decoupled
from the wind and decayed separately, as a new spectrum consistent with the wind direction was generated.
These observations confirm theoretical results previously obtained from a third generation
wave model. The relaxation of waves in turning winds was investigated using a simple relaxation model.
Correlation coefficients obtained in this study are higher than previously published studies, especially
for lower values of the wave age, and a relationship between the relaxation parameter and the wave age
is observed.

The purpose of “Sustainable Development” raises the following basic question: Which “indicator”
should be used to identify the human activities that are contrary to this purpose?
In this paper it will be shown that “Entropy Generation” constitutes this Indicator. To this purpose, we
will use three examples where Entropy Generation takes place and demonstrate that this generation of
entropy is always contrary to Sustainable Development.
A forecast of future human activities will be then presented which will demonstrate that large Entropy
Generation will continue. Sustainable Development can be thus achieved only by entering an “Era of
Reduced Entropy Generation”, which requires however drastic changes from Institutional policies to
our own values and way of life.