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The current improvements in aerosol mass spectrometers in resolution and sensitivity, and the analytical tools for mass spectra deconvolution, have enabled the in-depth analysis of ambient organic aerosol (OA) properties. Although OA constitutes a major fraction of ambient aerosol, its properties are determined to a great extent by the mixing characteristics of both organic and inorganic components of ambient aerosol. This work applies a new methodology to a year-long ACSM dataset to assess the sources of organic and total non-refractory species in the Athens background aerosol and provides insights into the interactions between organic and inorganic species. The use of innovative tools for applying positive matrix factorization (PMF, rolling window) enables the study of the temporal variability of the contribution of these sources and seasonal changes in their composition. The mass spectra of both organic and inorganic aerosol were obtained by a time-of-flight aerosol mass spectrometer (ToF-ACSM) for PMF analysis. The results revealed five factors when organic aerosol was analysed separately. Three of them were primary OA factors: hydrocarbon-like organic aerosol (HOA), cooking-related organic aerosol (COA) and biomass burning organic aerosol (BBOA). The remaining two were secondary, less and more oxidized oxygenated organic aerosol (LO-OOA and MO-OOA respectively). The relative contributions of these factors were HOA 15 %, COA 18 %, BBOA 9 %, MO-OOA 34 % and LO-OOA 24 % (yearly averaged). When a combined organic and inorganic aerosol matrix was analysed, two additional factors were identified that were mainly composed of ammonium sulfate (83.5 %) and ammonium nitrate (73 %). Moreover, two secondary factors were resolved, containing both organics and inorganics and were named more (MOA) and less oxidized aerosol (LOA). The relative contributions on a yearly average of these factors were HOA 7 %, COA 9 %, BBOA 3 %, ammonium nitrate 3 %, ammonium sulfate 28 %, MOA 24 % and LOA 26 %.

This research work focuses on the investigation of the Z-R relationship impact on weather radar rainfall estimates, through the correlation of a X-Band weather radar estimates and rain gauge measurements in the region of Attica, Greece. The methodology followed in this work is performed into two sections, where first, a framework is applied in order to access the raw rainscanner datasets and convert them into a compatible form for comparison, since the radar measurements consist of gridded reflectivity values of 2-min temporal scale, whereas the rain gauge measurements pertain to 10-min point precipitation measurements. Secondly, a statistical analysis is performed, regarding the spatial variability of the Z-R relationship for a single event. Specifically, four Z-R relationships are used and compared based on the correlation with the actual rain gauge measurements, for each station, and the results are then shown upon the study area. The results provide with important findings about the spatial distribution of the optimal Z-R relationship based upon the proximity of the stations to the weather radar location, the coastline and station elevation.

The current improvements in aerosol mass spectrometers in resolution and sensitivity, and the analytical tools for mass spectra deconvolution, have enabled the in depth analysis of organic aerosol (OA) properties. Although OA constitutes a major fraction of ambient aerosol, the overall aerosol properties are determined by the mixing characteristics of both organic and inorganic contents of ambient aerosol. In the present study, the mass spectra of both organic and inorganic aerosol were obtained by a time–of–flight aerosol mass spectrometer (ToF-ACSM) and further merged into one input matrix for Positive Matrix Factorization (PMF) analysis. The scope of this work was to assess the sources of organic aerosol and total non–refractory species in the suburbs of Athens, check their temporal variation and the interactions between organic and inorganic species, after reaching environmentally reasonable solutions for both matrices. The results revealed five factors in the case of the organic aerosol matrix. Three of them were primary OA factors: hydrocarbon–like (HOA), cooking related (COA) and biomass burning (BBOA), and the remaining two were secondary, less and more oxidized oxygenated organic aerosol (LO-OOA and MO-OOA, respectively). The relative contributions of these factors were HOA 15 %, COA 18 %, BBOA 9 %, MO-OOA 34 % and LO-OOA 24 % (yearly averaged). In the case of the combined aerosol matrix, two additional factors were identified that were mainly composed of ammonium sulfate (83.5 %) and ammonium nitrate (73 %). Moreover, the two secondary factors with both organics and inorganics were named as more (MOA) and less oxidized aerosols (LOA). The relative contributions on a yearly average of these factors were HOA 6 %, COA 9 %, BBOA 6%, Ammonium Nitrate 4 %, Ammonium Sulfate 28 %, MOA 23 % and LOA 24 %. The results showed a variation in secondary aerosols composition of organics and inorganics, mainly in less oxidized aerosol (LOA). This factor was composed primarily of organics during winter (80 %), while both organics and inorganics contributed equally to this factor in spring and summer; and in early autumn this factor presented more sulfate (70 %) than organics. This work presents a new methodology on ACSM data analysis, provides insights on the sources of the non–refractory species of ambient aerosols and using innovative tools for applying PMF (Rolling window) enables the study of the temporal variation of these sources and also the variability of their composition.

In the present work, a simulation-optimization method is employed in order to manage saltwater intrusion in two unconfined coastal aquifers in Crete, Greece. The optimization formulation seeks to maximize groundwater withdrawal rates while maintaining the saltwater intrusion front at the current location or inhibiting it at locations closer to the coast. A combination of a groundwater flow model (MODFLOW) with the Ghyben-Herzberg saltwater front approximation and a sequential implementation of the Simplex algorithm (GWM) are employed. The results show that under the current pumping strategies, the saltwater intrusion front will continue to move inland, posing a serious threat to the groundwater quality of these regions. Optimal groundwater withdrawal scenarios that take into consideration the water needs of the local communities and environmental concerns are presented and discussed. In both case studies, significant reductions in pumping are required in order for the saltwater intrusion front to retract closer to the shoreline.

During the last decade in Europe, membrane bioreactor (MBR) systems have been proven to be a very efficient technique for municipal and industrial wastewater treatment (WWT). The most obvious appeal of the MBR technology is that it produces a stable and excellent effluent quality and eliminates the need for good sludge settleability, as it is one of the basic requirements in conventional WWT plants. Due to both the compact footprint and the great potential for automation, MBR plants ensure precise control of the sludge residence time and the mixed liquor suspended solids, which are basic operating parameters. The above results in: (a) the reduction of the required reactor size, (b) the promotion of the evolution of specific nitrifying bacteria, and finally, (c) the production of less sludge. However, the effluent rate of MBRs is limited, mainly because of the membrane fouling effect. Membrane fouling is probably the most critical problem of the submerged membrane bioreactors (SMBRs), and the appli...

In the present study, 88 structurally- diverse drugs were investigated by biopartitioning micellar chromatography (BMC) using Brij-35 as surfactant under different chromatographic conditions. It was found that temperature and presence of NaCl have only a minor effect in BMC retention. Correlation of BMC retention factors with octanol-water partitioning required the inclusion of fractions of ionized species as additional parameters, showing that there is a weaker effect of ionization in BMC environment. Compared to Immobilized Artificial Membrane (IAM) Chromatography, BMC retention factors cover a relatively narrow span, two-fold smaller than retention factors on IAM stationary phases as a result of the presence of micelles facilitating elution of lipophilic compounds and the absence of secondary attractive electrostatic interactions in the BMC environment. Similarities/dissimilarities between BMC, octanol-water partitioning and IAM Chromatography were investigated by Linear Free Energy Relationships (LSER). BMC retention factors were used to construct relationships with cell permeability,% Human Oral Absorption (%HOA) and Plasma Protein Binding (%PPB). Linear BMC models were obtained with Caco-2 cell lines and Parallel Artificial Membrane Permeability Assay (PAMPA). For %HOA, a hyperbolic model was established upon incorporation of topological polar surface area (tPSA) as additional parameter. A sigmoidal model was constructed for %PPB and a linear one for the corresponding thermodynamic binding constant logK. In both cases inclusion of the fraction of anionic species with a positive sign was required reflecting the preference of human albumin for acidic drugs.

The effective management of Graves' disease (GD) during pregnancy is crucial for maternal and neonatal well-being. Conventional treatment of GD during pregnancy includes antithyroid drugs (ATDs) and surgery, ideally during the second trimester. We report a 27-year-old woman with GD and we present the course of GD during her three consecutive pregnancies. During the first pregnancy, thyrotoxicosis was successfully treated with low doses of antithyroid drugs; in the second pregnancy, thyrotoxicosis was only controlled at the third trimester; while in the third pregnancy, our patient presented with treatment-resistant thyrotoxicosis, which was finally managed with corticosteroids in adjunction with ATDs. Although hyperthyroid, the patient maintained her fertility. Resistance to ATD is a rare condition and in our case was adequately controlled with corticosteroids.

Search and Rescue (SaR) in forest fires is usually applied in a broad area, under foggy or smoky conditions. It mostly involves location of entrapped fire crew or people in between fire fronts, as well as, safely removing them away from the dangerous zone. Moreover, SaR is applied in evacuation of rural residential areas due to heavy smoke impacts, or fire front approaching. Experiences achieved during a field trial, in which unmanned aerial and ground vehicles were deployed and used in a simulated forest fire SaR scenario, are presented. For planning and running the field trial a number of parameters were taken into consideration; logistics, safety plan, contingency plan, different agencies cooperation, time frames and ethical issues. Advantages of using unmanned aerial and ground vehicles in SaR operations include capability of planning and monitoring the operations, integration with the manned resources, connectivity with command and control centers, as well as, coordination of the different unmanned aerial and ground vehicles' platforms. Significant increase of personnel safety is possible through the capabilities of air quality monitoring and search over dangerous areas. Current limitations include limited heat resistance of vehicles and limited flying capability in strong winds and turbulence. Failure of communications is also possible due to rough terrain (autonomy limitations). Against all the limitations, a number of unmanned vehicles already exist that can be adapted successfully for SaR operations in forest fires.

Membrane bioreactors (MBRs) in wastewater treatment have gained significant popularity recently, especially due to reclamation needs. Submerged membrane bioreactors (SMBRs) are considered to be an extremely successful method for this purpose. However, membrane fouling is one of the most critical problems of the SMBR systems, and the used techniques to avoid this problem have the disadvantage of the high energy needed. The objective of this study was to introduce an alternative cleaning technique of submerged membranes, with reduced energy consumption. A lot of lab studies have been published concerning the impact of mechanical action in the removal of foulants from the membranes (e.g. vibration, buck-pulse, and ultrasound). In this preliminary study, the feasibility of high frequency power (or powerful) vibration (HFPV), as cleaning technique, on fouled membrane modules, in a small pilot-scale SMBR system, treating a novel synthetic wastewater was examined. This pilot-scale system comprised from s...

Long term fire retardant (LTR) application for forest fire prevention purposes as well as wildland fires can result in chemical leaching from forest soils. Large quantities of sodium (Na), aluminium (Al), iron (Fe), manganese (Mn), copper (Cu) and silicon (Si) in leachates, mainly due to ammonium (one of the major LTR components) soil deposition, could affect the groundwater quality. The leaching of Na, Al, Fe, Mn, Cu and Si due to nitrogen based LTR application (Fire Trol 931) was studied at laboratory scale. The concentrations of Na(+), Al(3+), Fe(3+)/Fe(2+), Mn(2+), Cu(2+) and Si(4+) were measured in the resulting leachates from pots with forest soil and pine trees alone and in combination with fire. The leaching of Na, Fe and Si from treated pots was significantly greater than that from control pots. The leaching of Al, Mn and Cu was extremely low.

Sea buckthorn is a promising source of bioactive compounds. However, there is limited information on the effect of post harvest drying and extraction of sea buckthorn on its antioxidant capacity. The effect of freeze, air, and solar dryingon the extraction yield of sea buckthorn berries and leaves was evaluated with respect to their bioactive content. Sequential extraction with solvents of different polarity and solvent-free microwave-assisted extraction were applied. Freeze-drying has better performance in the berries’ extracts, while air-drying has better performance in the leaves’ extracts. All data were analyzed by Multi Factor Analysis of Variance (ANOVA) and Duncan's post-hoc tests at a level of α = .05. Although the extraction yield in the sequential extraction of sea buckthorn berries is significantly better, the leaves’ extracts exhibit superior radical scavenging ability. Accelerated solar drying appears to preserve sea buckthorn leaves without degrading their antioxidant content. The components...

Thermal properties of new extruded products with texturized properties were examined using Differential Scanning Calorimetry (DSC). Corn-texturized protein systems were extrusion-cooked in a twin-screw extruder with varying feed rate (0.7–1.9 g/s), screw speed (150–250 rpm), extrusion temperature (150 to 260°C), and feed moisture content (13 to 19 g/100g wet basis). Four different texturized legume flours, namely bean, chickpea, kidneybean, and lentil were mixed with corn grits. A simple mathematical model was used to correlate the melting transition temperature with the extrusion conditions and moisture content. As expected, phase transition behaviour and thermal properties of the corn-water-legume system depend significantly on product temperature, feed moisture and corn/legume ratio and less on screw speed and feed rate.

The present laboratory study was conducted in pot soil taken from forest. The leaching of calcium (Ca), magnesium (Mg), and potassium (K) (plant macronutrients) due to the application of a nitrogen phosphate-based long-term fire retardant (LTFR) (Fire Trol 931) was investigated. The concentrations of Ca(2+), Mg(2+), and K(+) were measured in the resulting leachates from pots with forest soil and pine tree alone and in combination with fire. Magnesium is a minor component of Fire Trol 931. The leaching of Ca(2+), Mg(2+), and K(+) from treated soils with the retardant pots was significantly greater than that from control pots. The leaching of Mg(2+) was found to be of small percentage of the initially applied Mg quantities. Fire Trol 931 application resulted in the leaching of Ca(2+), Mg(2+), and K(+) from a typical Mediterranean forest soil in pots, following the application of simulated annual precipitation probably due to ammonium (one of the major retardant components) soil deposition that mobilizes base cations from the soil. It seems that LTFR application may result in chemical leaching from the soil to the drainage water.

Long-term fire retardant (LTR) use for forest fire suppression and/or prevention purposes can result in chemical leaching, from soil to the drainage water, during the annual rainfall period. Also, wildland fires can have an impact on the leaching of various chemicals from treated forest soils. Large quantities of ions in leachates, mainly due to ammonium (one of the major LTR components) soil deposition, could affect the groundwater quality. The alteration of pH, total hardness (TH), and electrical conductivity (EC) values in leachates mainly due to nitrogen-based LTR application (Fire Trol 931) was investigated in this laboratory study. The values of pH, TH, and EC were measured in the resulting leachates from pots with forest soil and pine trees alone and in combination with fire after a simulated rainfall period. pH, TH, and EC values in leachates from all treated pots were significantly greater than those from control pots.

Thermogravimetry-mass spectrometry (TG-MS) was used to study the effect of the inorganic salts (NH4)2SO4 and (NH4)2HPO4, active substances of many commercial forest fire retardants, on the pyrolysis of Pinus halepensis needles and their main components (cellulose, lignin and extractives). These salts seemed to affect the pyrolysis of cellulose by increasing significantly the char residue, decreasing the pyrolysis temperature and changing the composition of the evolved gases, that is, increasing levoglucosenone and decreasing oxygen containing volatile products. (NH4)2SO4 seemed to have negligible effect on the pyrolysis of lignin, while (NH4)2HPO4 increased the char residue and decrease the relative contribution of guaiacols in the evolved gases. No effects of the inorganic salts on the extractives were observed. Finally, the inorganic salts seemed to affect the pyrolysis of pine-needles, mainly the cellulose component, but the effects were not as intense as in the pyrolysis of cellulose.

Structural properties, such as apparent density, true density, expansion ratio and porosity, of extruded corn grits were measured. Corn grits were extrusion-cooked in a Prism extruder with varied feed rate (1.16–6.44 kg/h), screw speed (150–250 rpm), product temperature (100–260 °C) and feed moisture content (12–25 kg/100 kg wet basis). A simple mathematical model was used to correlate the examined properties with the extrusion conditions. Extruded product apparent density, porosity and expansion ratio were found to be dependent on feed moisture content, residence time and temperature while they were not affected by screw speed. More specifically, the apparent density of extruded products had an increasing trend with feed moisture content and residence time, while it decreased with product temperature. Porosity and expansion ratio of extruded products decreased significantly with feed moisture content and residence time, while temperature rise resulted in products of higher porosity and expansion ratio.

The design, the abilities and a characteristic application of an in-house made interface for combining thermogravimetry (TG) with mass spectrometry (MS) are presented. The TG-MS interface consists mainly of three co-axial tubes. The position of the intermediate tube was determined after calculation of the temperature profile at the TG furnace exit tube. The inner tube position was determined taking into consideration its protection against condensation of heavy molecules and the time delay for the transfer of the evolved gases. This interface allows either continuous sampling and transferring of the evolved gases from the TG to the MS or repetitive introduction of short sampling pulses of TG evolved gases to MS. The interface is capable of coupling various commercial instruments. In the present work two configurations of this interface are demonstrated. Finally an example of application of this interface on forest fuel pyrolysis is presented.

Objective To assess the effect of treatment with a combination of the antiestrogen tamoxifen citrate and the androgen testosterone undecanoate on sperm variables and pregnancy incidence in men with idiopathic oligozoospermia and couple subfertility. Design Prospective, randomized, placebo-controlled trial. Setting Clinical research in a tertiary care academic hospital. Participant(s) Two hundred twelve men with idiopathic oligozoospermia and 82 normozoospermic men with female factor subfertility. Intervention(s) Oligozoospermic patients were randomly assigned to two treatment groups with tamoxifen citrate, 20 mg/d, and testosterone undecanoate, 120 mg/d (n = 106) or placebo treatment (n = 106) for 6 months. Normozoospermic men were followed for the same period. Couple counseling was part of the intervention in all groups. Main outcome measure(s) Pregnancy incidence and sperm characteristics after 3 and 6 months on medication and 3 months after the end of the trial. Result(s) In the active treatment group, total sperm count (median [25th, 75th percentile], 27.1 × 10 6 cells/mL [9.4, 54.0 × 10 6 cells/mL] at baseline and 61.5 × 10 6 cells/mL [28.2, 119.6 × 10 6 cells/mL] at 6 months), progressive motility (mean [±SD] , 29.7% ± 12.0% at baseline and 41.6% ± 13.1% at 6 months), and normal morphology (mean, 41.2% ± 14.0% at baseline and 56.6% ± 11.5% at 6 months) were noted. No marked changes were observed in placebo recipients or normozoospermic men. The incidence of spontaneous pregnancy was 33.9% in the active treatment group and 10.3% in the placebo group (36 vs. 11 pregnancies), with a relative risk of 3.195 (95% CI, 2.615 to 3.765). Conclusion(s) Treatment with tamoxifen citrate and testosterone undecanoate improved sperm variables and led to a higher incidence of pregnancy in couples with subfertility related to idiopathic oligozoospermia.

Chemometric methods were used for extracting information out of the mixture mass spectra recorded in a thermogravimetric–mass spectrometric (TG–MS) analysis. Principal Component Analysis (PCA) and Discriminant Rotation (DR) were applied for studying the effects of fire retardants on the gases evolved during thermal degradation of cellulose. The chemicals (NH 4 ) 2 SO 4 , (NH 4 ) 2 HPO 4 and a commercial retardant (Fire Trol) were used as fire retardants. PCA and DR resulted in four factors discriminating between untreated cellulose and cellulose treated with fire retardants. For the interpretation of the factors the rotated discriminant spectra were used. For estimating the effects of the fire retardants, the score plot in the first two discriminants space was used. It was shown that in all cases the retardation action was based on various factors such as: the increase of CO 2 evolution produced by dehydration of cellulose, the relative decrease of very flammable volatile products (carbonyl compounds, reduced furans and pyranone derivatives) and the increase of levoglucosenone produced by dehydration of levoglucosan. A differentiation between the effects of (NH 4 ) 2 SO 4 and the other two retardants was also observed and it concerned mainly the production of phenol derivatives and acetic acid.

Introduction. Plasma antithyroid peroxidase (anti-TPO) and anti-thyroglobulin antibodies (anti-Tg) are widely used in the diagnosis of autoimmune thyroiditis. No research has compared anti-TPO and anti-Tg both in plasma and cerebrospinal fluid (CSF) of healthy individuals vis-à-vis patients with thyroid disease.Methods. We measured anti-TPO and anti-Tg antibodies in plasma and CSF in nine subjects (mean age ± SD: 73 ± 6 years) with hypothyroidism and nine subjects (mean age ± SD: 73 ± 8 years) without thyroid disease.Results. The concentration of anti-TPO autoantibodies in CSF was very low compared to plasma in both subjects with thyroid and without thyroid disease (P=0.007). CSF anti-Tg autoantibodies titers were very low compared to the plasma in subjects with thyroid disease (P=0.004), whereas, in subjects without thyroid disease, this difference did not reach statistical significance (P=0.063).Conclusions. Thyroid autoantibodies levels were low in plasma and CSF; we did not observe any transfer of thyroid autoantibodies from the peripheral blood to the CSF. Therefore, regarding Hashimoto’s encephalopathy, where elevated antithyroid autoantibodies are often measured in blood, it is more likely that thyroiditis and encephalopathy represent nonspecific, but distinct, events of an aggressive immune system.

Factor Analysis was used for extracting information out of the mixture mass spectra recorded in a thermogravimetric–mass spectrometric analysis. Principal component analysis (PCA) and a special diagram, the contour variance diagram (ContVarDia), were used for performing the factor analysis. The method was applied for studying the thermal decomposition of Kraton 1107 copolymer. Pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS) was used for identification of the pyrolysis products of Kraton 1107. The application of factor analysis resulted in the determination of the main thermal decomposition steps and the prediction of the mass spectrum corresponding to each step. Those mass spectra were either pure spectra corresponding to main evolved gases or average spectra corresponding to multiple gases evolved in one decomposition step. The advantages and the limitations of the chemometric approach were discussed. © 2002 Elsevier Science B.V. All rights reserved.

Two microscopic techniques, transmission light microscopy (LM) and stereoscopy, were used for studying the effect of fire retardants on the pyrolysis of Pinus halepensis needles. Pure (NH 4 ) 2 HPO 4 and a commercial product (Fire Trol), based on polyphosphates as the active chemical retardant, were tested as fire retardants. With increasing pyrolysis temperature, the loss of the cuticle layer, the cracking of the epidermal cells, the charification of the inner part and the degradation of the lignin content of the needles were observed by LM. LM showed that all these phenomena were accelerated (shifted to lower temperatures) in those treated with fire-retardant needles compared with the untreated ones. Stereoscopy was used for monitoring changes on the external surface of the pyrolyzed needles such as changes concerning the retardant itself and the tar and char formation. It appeared that, in the presence of the retardants, tar and char formed at lower pyrolysis temperatures and at a greater extent compared with the untreated needles. In all cases studied, the commercial product appeared to be more effective than the pure (NH 4 ) 2 HPO 4 . The recorded observations were associated with the chemical and physical phenomena occurring during the pyrolysis procedure and the theory of the fire retardation action of the chemicals.

Principal component analysis (PCA) was applied to the noise reduction of low ppb level benzene, toluene, ethyl benzene, xylene (BTEX) type gas chromatography/mass spectrometry (GC/MS) measurements (i.e. BTEX) with a fast, repetitive GC/MS system. The first three principal components (PCs) accounting for approximately 60‐80% of the total variance in the original data could be attributed to chemical components, whilst the remaining PCs were found to be due to noise. Reconstruction of the data from the first three PCs resulted in noise reduction with improved signal fidelity. The results of PCA were comparable with those achieved by a Fourier transform method. ©1999 Elsevier Science B.V. All rights reserved.

Pyrolysis gas chromatography with flame ionization detector (Py-GC-FID) and pyrolysis gas chromatography with mass selective detector (Py-GC-MSD) were used for studying the effect of (NH4)2HPO4 and (NH4)2SO4 on the pyrolysis of Pinus halepensis pine-needles. Flash Py-GC-MSD analysis of the pine-needles at 400°C, showed differences in the composition of the organic volatile products after treatment with chemicals. The major ones were the formation of new products such as levoglucosenone due to the alteration of thermal degradation mechanism, or due to the interaction of chemicals with the pine-needles pyrolysis products like benzonitrile. Py-GC-FID was applied to pine-needles in a temperature region of 100–600°C, for monitoring changes regarding the evolution profile of various pyrolysis products, as well as their pyrolysis temperature shifting in the presence of chemicals. The Py-GC-MSD and Py-GC-FID proved to be effective and promising methods for the elucidation of retardation mechanisms during the pyrolysis of pine-needles.

A pneumatic sampling switch which can be adapted to the outlet of a thermogravimetric analyzer furnace with a horizontal purge gas flow was developed. This system allows a repetitive introduction of short sampling pulses of thermogravimetric analyzer evolved gases to a quadrupole mass spectrometric detector. System performance was evaluated through measuring the level of repeatability under different operation conditions. In addition, pulsed sampling thermogravimetry/mass spectrometry introduced no measurable quantitative or qualitative errors. This system can be used for monitoring thermooxidative decomposition reactions, without accelerating the deterioration of quadrupole mass spectrometric detector performance. Furthermore, it can be used as an inlet system for a future on-line TG/GC/MS system.

Five years data on CO, NO, NO2, O3, smoke and SO2 concentrations recorded at oneair-pollution monitoring station in the city of Athens were analysed using principal component analysis(PCA). Separate analyses were undertaken for summer and winter periods. PCA was also applied tometeorological data concerning relative humidity, temperature, sunshine duration, wind velocity and winddirection. It was found that the main principal components extracted from the air pollution data wererelated to gasoline combustion, oil combustion and ozone interactions. The most prominent principalcomponents from the meteorological data were related to dry conditions (summer period) and high-speedsothwestern winds (for both periods). Finally, canonical correlation analysis determined relationshipsbetween the two different data sets. The main relationship was between total pollution and high humidity incombination with the low-velocity wind.

Various electrochemical methods such as oxidation-reduction potentiometry, pH-metry and conductometry were used for monitoring the volatile pyrolysis products of Pinus halepensis pine-needles. The study was carried out under non-isothermal conditions (ambient to 400 °C) with a heating rate of 10 °C min −1 , in nitrogen atmosphere. Products with the lowest redox potential values, such as aldehydes and alcohols, were evolved between 180 and 230 °C. Products with the highest conductivity values such as carboxylic acids, were evolved in the temperature range of 240–320 °C, whilst those with the lowest pH values, such as phenols and acids were evolved in the temperature range of 220–300 °C. The results of this study are in agreement with those obtained previously by DI-MS, Py-GC-FID and Py-GC-MS. The electrochemical methods have the advantage of being simple, fast and low cost methods for monitoring the pyrolysis products. The redox potential value is examined as a measure of the chemical stability (i.e. the reducing properties increase as the redox values decrease) correlated with the flammability of the pyrolysis products.

The analytical methods of DSC, TG, DI-MS, Py-GC-FID, Py-GC-MSD were used to study the thermal degradation of Pinus halepensis pine-needles. As was shown by DSC measurements endotherm peaks could be attributed to the desorption of high volatility compounds, moisture, softening and/or melting of the waxy constituents of pine-needles; as well as to the degradation of hemicellulose and cellulose. Exotherm peaks could be attributed to the pyrolysis of lignin and char recombination. These results were reconfirmed by DTG curve. In addition, the DI-MS measurements showed, through the presence of certain mass peaks, the existence of volatile degradation products which can be related to the degradation pathways observed by DSC and TG. Py-GC-FID proved that the evolution of organic degradation products commences at 200–250 °C and has its maximum evolution rate between 350 and 450 °C. Py-GC-MSD analysis of the flash pyrolysis products at 400 °C identified a number of organic compounds and CO 2 .

Pyrolysis gas chromatography (PY-GC) was used for studying the effect of (NH 4 ) 2 HPO 4 and (NH 4 ) 2 SO 4 on the pyrolysis of cellulose. The major constituents of volatile organic pyrolysis products were examined, and the changes of their composition in the presence of the above chemicals were determined. PY-GC proved to be an effective and promising method for the elucidation of retardation mechanisms during pyrolysis.

The trends for such important parameters of male fertility as seminal volume and total sperm number were assessed in men living permanently in the Greater Athens area over a prolonged period of time. To this end, the records of three andrological laboratories employing the same method for semen evaluation were analysed retrospectively. Out of 23,850 men examined from 1977 to 1993 (17 years) for couple subfertility, a total of 2385 (10%) were selected for evaluation by a randomization procedure. Analysis of the data included (i) estimation of mean seminal volume and total sperm number per year, (ii) assessment of percentage frequency distribution of each seminal parameter and (iii) evaluation of seminal volume and total sperm number changes in relation to the year of observation and age of the subjects. A significant decrease (P < 0.01) of total sperm number was observed over the years with a mean (+/-SEM) of 154.3 +/- 19.2 x 10(6) at the beginning (1977), dropping to 130.1 +/- 13.3 x 10(6) in the final year (1993). Mean seminal volume was lower in the final year of observation, but its difference from the initial year value was not significant. Frequency distribution analysis showed a marked decline in the 240-400 x 10(6) sub-set of the range of sperm number values from 16.9 +/- 4.5% (1977) to 10.6 +/- 1.6% in the final year (P < 0.01). Multiple regression analysis of seminal volume, total sperm number, age and year of assessment revealed a significant decline of the two seminal parameters along the years of observation (P < 0.05 and P < 0.0001 respectively). Over the same period, a marked deterioration of some air pollution indices was observed in that area. It is concluded that in this racially and ethnically homogeneous sample of men, living under the same environmental conditions, a significant decline in seminal volume and total sperm number occurred over the 17 years of observation.

Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) were used to study the effects of various salts and oxide-hydroxide additives on the pyrolysis of cellulose and Pinus halepensis pine needles. (NH4) 2 HPO 4 , NaH 2 PO 4 , (NH 4 ) 2 SO 4 , NaHCO 3 , KHCO 3 , (COONa) 2 , Ca(OH) 2 and Na 2 O.CaO were used as additives at concentrations of 4% w/w and 10% w/w. DSC and TGA showed that the addition of (NH 4 ) 2 HPO 4 , NaH 2 PO 4 and (NH 4 ) 2 SO 4 on cellulose causes a significant shift to lower pyrolysis temperatures, i.e. 50°C to 80°C, as well as a significant increase in char residues. The effect of NaHCO 3 , KHCO 3 , and (COONa) 2 on the pyrolysis of cellulose was also found to be significant in terms of the DSC profile, while the increase in char residues was moderate. In contrast the effect of Ca(OH) 2 and Na 2 O·CaO on the pyrolysis of cellulose was found to be minor, under the above-mentioned criteria. The above chemicals, tested as fire retardants, have shown minor effects on the pyrolysis of Pinus halepensis pine needles. Some changes, however, were noticed in the solid pyrolysis residues, particularly when (NH 4 ) 2 HPO 4 and (NH 4 ) 2 SO 4 were used.

DSC and TG were used to study the effects of fire retardants on the pyrolysis of Pinus halepensis pine-needles and their components (cellulose, lignin and extractives). (NH4)2HPO4 and (NH4)2SO4 were used as fire retardants at the 10% w/w concentration level. The TG results showed that the mass loss profile of pine-needles resembles those of lignin and extractives. The DSC curves showed that in the presence of fire retardants there is a shift to lower pyrolysis temperatures for cellulose. In addition, there is an increase in the pyrolysis residue for both cellulose and pine-needles. Minor or negligible effects were observed for lignin and extractives in the presence of the retardants.

Differential scanning calorimetry (DSC) and direct inlet mass spectrometry (DI-MS) were used for studying the effects of fire retardants on the pyrolysis of cellulose and Pinus halepensis pine-needles. The compounds (NH4)2HPO4 and (NH4)2SO4 were used as fire retardants at various concentration levels. DSC showed that the addition of the fire retardants results in a shift to lower pyrolysis temperatures for cellulose and in an increase in the pyrolysis residues for both cellulose and pine-needles. DI-MS was used for monitoring the evolution rate of various pyrolysis products and for the identification of the various pyrolysis phases.

In this work a new method called TG-bridge/mass spectrometry is presented, for the on-line monitoring of the pine needles combustion emissions in a common lab furnace. The TG-bridge (thermogravimetry-bridge) system has been developed in-house as a TG-MS (thermogravimetry-mass spectrometry) interface, for TG-MS analysis. In this work, TG-bridge was used for directly sampling of the combustion emissions from the inside of the furnace and transferring them into the mass spectrometer (MS), without disturbing the sub-pressure conditions inside the MS ion source. The effect of Fire-Trol 931 (a long-term fire retardant) on the emissions, produced during the combustion of pine needles, is tested in the lab for future application in the field. It was shown that in treated samples, increased evolution of ammonia and aromatic compounds took place, compared to untreated samples. Maximum concentrations of specific compounds, such as benzene and toluene, evolved during the combustion experiments in the furnace, were determined.

Sertoli cell functional reserve was assessed in normozoospermic men and oligozoospermic patients and its prognostic potential was evaluated for patient selection and treatment. For the first objective, three groups of normo-follicle-stimulating hormone (FSH)/normozoospermic fertile men (n:12), normo-FSH/oligozoospermic (n:21) and hyper-FSH/oligozoospermic subfertile men participated in the study whereas for the second objective 24 normo-FSH oligozoospermic patients volunteered for a pilot therapeutic trial. For the first part, high purity (hp) FSH (225 i.u., i.m.), human chorionic gonadotropin (hCG) (1500 i.u., i.m.) or their combination was given separately at weekly intervals, with samplings at 0, 3, 24 and 48 h. For the pilot trial, rec-FSH (150 i.u./48 h, i.m.) or placebo were prescribed for 6 months. The main outcome measures for the study were inhibin-B (inh-B), insulin-like growth factor (IGF)-I, testosterone and oestradiol concentrations and the main sperm parameters. Bolus administration of hp-FSH or hp-FSH/hCG combination in normozoospermic men resulted in a significant rise of inh-B in normozoospermic men (mean +/- SD, basal: 183.8+/-24.2 pg/mL in hp-FSH and 175.2+/-23.5 in hp-FSH/hCG treatment; 48 h: 256.1+/-34.2 and 246.3+/-19.0, respectively, p0.001 for both). In oligozoospermic groups basal inh-B concentration was lower than in normozoospermic men (normo-FSH: 117.4+/-16.5, hyper-FSH: 81.2+/-19.8, p0.001 for both) with a post-stimulation increase noted only in normo-FSH patients (hp-FSH 24-h: 132.8+/-19.7, p0.01; hp-FSH/hCG 0 min: 105.7+/-20.1, 24-h: 119.5+/-20.6, p0.05). Total sperm number and progressive motility showed significant improvements (p0.05 for both) after 6 months of rec-FSH treatment in the group of patients with a satisfactory response to hp-FSH stimulation. In conclusion, the basal and reserve activity of Sertoli cells, as judged by inh-B secretion, was higher in normozoospermic than in dyspermic men, with a better therapeutic outcome noted in those patients with an adequate response to hp-FSH stimulation.