Plants In Greece Research Articles

Antifungal Activity of Secondary Metabolites of Centaurea raphanina ssp. mixta, Growing Wild in Greece

The present study was carried out on the aerial parts of C. raphanina Sm. ssp. mixta (DC.) Runemark (Asteraceae), which is a commonly edible plant in Greece, on maturation stage. Although the isolation procedure is the appropriate one for the isolation of sesquiterpene lactones, the analysis revealed the presence of only one sesquiterpene lactone, namely cnicin, in small amounts. The main compounds were found to belong to polyphenols. The in vitro antifungal activity of the isolated compounds was tested, using the micro-dilution method. Only cnicin has been proved to be active against all fungi tested with a fungicidal potential higher than miconazole.

Development and Use of an Economic Evaluation Model to Assess Establishment of Local Centralized Rural Biogas Plants in Greece

An economic evaluation model was developed in the Laboratory of Agricultural Structures (LAS) of the Agricultural University of Athens-the Modified Basic Economic Evaluation Model (MBEEM). This model is an improved version of the original Basic Economic Evaluation Model, available in LAS, and it is used to assess the cost-effectiveness of biogas production systems. Because of the parameters involved, a computer model was developed to facilitate the application of the MBEEM. The model was used in this work to determine the cost-effective size of a local centralized biogas production system fed with pig wastes.

Sludge utilisation in agriculture: possibilities and prospects in Greece

The paper presents the prospects for agricultural utilisation of the sludge produced from wastewater treatment plants in Greece and more specifically focuses on a critical review of the legislatory framework, determination of the quantitative and qualitative characteristics of the produced sludges, examination of possible sludge treatment methods and evaluation of the possibilities and prospects of sludge utilisation on the basis of the above considerations. Landfilling is practically the only route to sludge disposal in Greece. However, in view of the anticipated future restrictions for landfilling within the European Union, this method is clearly a short-term solution and alternative options, including agricultural reuse, must be implemented. The results of a recent survey are presented and discussed in relation to this need.

Activation of soil respiration and shift of the microbial population balance in soil as a response to Lavandula stoechas essential oil.

Lavandula stoechas, a native plant of Greece, is rich in essential oil and fenchone is its major constituent. We examined the effect of the essential oil and its main constituents on soil metabolism and microbial growth. Addition of the essential oil or fenchone to soil samples induced a remarkable increase in soil respiration. This was accompanied by an increase in the soil bacterial population of three orders of magnitude. This sizable population was not qualitatively similar to that of the control soil samples. One bacterial strain dominated soil samples treated with L. stoechas essential oil or fenchone. By use of the disk diffusion assay, we evaluated the capacity of three bacterial strains that we isolated from the soil samples, as well as Escherichia coli and Bacillus subtilis (reference strains), to grow in the presence of the essential oil and three of its main constituents (fenchone, cineol, alpha-pinene). The substances tested did not inhibit the growth of the strain found to dominate the bacterial populations of treated soil samples; they severely inhibited B. subtilis. The other two isolated strains could also grow in liquid cultures in the presence of different quantities of essential oil or fenchone. Addition of fenchone at the end of the exponential phase increased the cell numbers of the strain that dominated the bacterial populations of treated soil samples, indicating use of the substrate added. On the basis of these results, we propose a scheme of successional stages during the decomposition process of the rich-in-essential-oil litter of aromatic plants that abound in the Mediterranean environment.

AN EFFICIENT META-HEURISTIC ALGORITHM FOR ROUTING PRODUCT COLLECTING VEHICLES OF DEHYDRATION PLANTS. II. ALGORITHM PERFORMANCE AND CASE STUDIES

Routing of vehicle fleet for collecting newly cropped raw materials for multi-product dehydration plants is a component of plant production schedule of utmost significance. A meta-heuristic algorithm for efficiently solving the collecting vehicle routing problem was developed and analyzed in detail in Tarantilis and Kiranoudis (2000). Meta-heuristic algorithms are broadly characterized by a stochastic nature in producing tender solution configurations in linear search terms, which sweep the huge solution space in a guided and rational way. Algorithm performance is examined through an analysis of the impact of model parameters on solution procedure during the execution of typical routing problems. The most important model parameter examined was found to be the value of the initial threshold as well as the way that the value of this actual parameter is appropriately adjusted during the optimization process. The main characteristic of the algorithm is the way that threshold is not only lowered but also raised, or backtracked, depending on the success of the inner loop iterations to provide for an acceptable new solution that would replace an older one. An important feature of the algorithm is the fact that appearance of better configurations within a process run is distributed according to the Poisson probability distribution. The suggested algorithm is tested against typical literature benchmarks as well against real-world problem encountered in the production planning procedures of dehydration plants in Greece.

The economic viability of commercial wind plants in Greece a complete sensitivity analysis

The economic viability of commercial wind plants in Greece a complete sensitivity analysis

A south east Asian pest species newly recorded from Europe: Thrips parvispinus (Thysanoptera: Thripidae), its confused identity and potential quarantine significance

The south east Asian pest thrips, Thrips parvispinus is recorded breeding in Europe for the first time, damaging Gardenia plants in Greece. Morphological variation in this species from various Asian countries is recorded and compared to the type specimens. As a result Isoneurothrips jenseni Karny, 1925 and Thrips (Isoneurothrips) taiwanus Takahashi, 1936 are placed as synonyms of Thrips parvispinus (Karny, 1922). In contrast, Thrips compressicornis (Sakimura), a species from the Marquesa Islands of the Pacific that has previously been associated with these taxa, represents a very different species. The quarantine significance of T. parvispinus is emphasised.

The economic viability of commercial wind plants in Greece A complete sensitivity analysis

The influence of the governing techno-economic parameters on the economic behaviour of commercial wind parks is investigated. For this purpose, a complete cost–benefit analysis model, properly adapted for the Greek market, is developed in order to calculate the pay-back period and the economic efficiency of similar investments in the energy production sector. Moreover, the impact of various parameters — such as capital cost, return on investment index, local inflation rate index, electricity price escalation rate, installation capacity factor, M&O cost, turn-on key cost of the power plant, size of wind turbines used — on the economic viability and attractiveness is extensively investigated, using a well-elaborated simple “expert system” type numerical code. Finally, the prediction results are summarised in a representative sensitivity analysis map, including the most reasonable economic scenarios. Taking into account the analytical results of the proposed study along with the existence of high wind potential regions in Greece, a remarkable growth of the wind energy sector is expected in the near future, leading to considerable investment profits and offering a strong position (share) of the liberalised local power market.

Small municipal wastewater treatment plants in Greece

Data from 147 small municipal wastewater treatment plants (MWTP), with a population equivalent (p.e.) less than 10,000, have been collected and analysed. Extended aeration plants are the most common (75%), followed by natural systems - waste stabilisation ponds (9%) and hydroponic silviculture (6%). Only 71 MWTP (out of the 147) were operational in 1997; the performance of only 15 of these was good, for 36 was moderate and for 20 it was poor. It was found that the reasons for poor performance, for the plant failure and for delays in commissioning were managerial and institutional, rather than purely technical.

Recycling of spent lead/acid batteries: the case of Greece

Abstract In this study, the application of modern recycling technologies in accordance with the European and Greek legislation, aiming at the recovery of lead, polypropylene and sulfuric acid from spent lead (Pb)/acid batteries, is presented. The present state of their disposal and exploitation is also depicted. The international situation is reviewed, the general trends are marked and the main technologies related to lead/acid battery treatment are reported. General recommendations are given regarding the collection of spent batteries and the installation of a recycling plant in Greece. A sensitivity analysis is carried out in order to define the most significant parameters affecting the viability of a recycling scheme. The present study proves that a possible installation of a Pb/acid batteries recycling process unit, treating 17 000 t/year (estimated total quantity) and situated in the industrial area of the greater Athens region, seems to be economically profitable. The already existing operation of small-scale battery recycling plants, common in small countries, should be discouraged as they demonstrate a rather not environmentally acceptable recycling operation.

Currant-wastewater treatment using biological and physicochemical processes

There are about 30 currant- and sultana-finishing plants in Greece. Methods of washing-water use and wastewater treatment and analysis are described. A case study of currant-wastewater treatment is analysed. Chemical coagulation, acidification, methanization, extended aeration, evapotranspiration are used. Advanced oxidation of treated effluent using physicochemical processes was applied to decrease COD and colour to values appropriate for irrigation and underground aquifer recharge.

P4F117 - Monitoring of fluoride content in the environment around an aluminium smelter plant

The effects of fluoride emissions, from an aluminium reduction plant in Greece, on the concentration of fluoride in soils and natural vegetation and also the relation between injury and fluoide content of plants were investigated.Fluoride emissions from the factory caused toxicity to natural vegetation in the adjoining area. Some plant species accumulated high fluoride levels in the leaves and exhibited acute necrosis, chlorosis or both. Others did not show visible injury, in spite of their high fluoride accumulation. The intensity of symptoms changed a great deal from one individual plant to the other or even from leaves of the same plant.The average levels of fluoride in vegetation ranged from 621.2 to 257.2 ppm in severely damaged areas (zone I) and from 144.3 to 64.1 ppm in lightly damaged areas (zone III). The corresponding fluoride levels in the controls was 15.4−8.2 ppm. In soils total fluoride concentrations ranged from 823.5 to 297.6 respectively; the levels in controls ranged from 108.6 to 95.3 ppm.

An auditing methodology for safety management of the Greek process industry

Process Risk Management Audit (PRIMA), a methodology aiming at assessing the impact on safety of the management system in a plant is outlined. The methodology has been applied in two plants in Greece within the framework of a cross-national application and results concerning both the methodology and the Greek plants are reported and discussed.

Determination of polychlorinated dibenzodioxins and dibenzofurans in fly ash

Polychlorinated Dibenzo-p-dioxins (PCDD) and Dibenzofurans (PCDF) in fly ash samples from coalburning power plants in Greece have been determined by high resolution gas chromatography combined with mass spectrometric detection (HRGC-MS) applying the isotopic dilution technique. Concentrations of PCDFs were 20 to 600 fold higher than for PCDDs. The concentrations of PCDDs and PCDFs were in the range of 11–62 and 1254–7180 pg/g respectively. Fly ashes from coal-burning power plants were found to be potential sources of PCDFs.

Threatened species not necessarily rare, rare species not necessarily threatened

In the beautifully-illustrated book of rare and threatened plants of Greece (Phitos et al. 1995), the selection of species is based strictly on the four World Conservation Union (IUCN) categories of ‘extinct’, ‘endangered’, ‘vulnerable’ and ‘rare’ (Lucas & Synge 1978). The Swedish ‘red data’ book of plants (Aronsson et al. 1995) adds ‘care-demanding species’ to the list. Five percent of the total number of vascular plant species in Greece are included in the Greek book, while 23% of the vascular plant species in Sweden are in the Swedish book. This latter percentage may appear to be sufficiently large, but is it?

Microbiological quality of bottled water in Greece

microbiological quality of the water produced by 38 bottling plants in Greece between 1987 and 1992 is presented and discussed. The presence of Pseudomonas spp. is also considered.

Plant protection problems caused by phytonematodes in Greece1

The major nematode pests of cultivated plants in Greece include root‐knot nematodes Meloidogyne spp. (in almost all plants except citrus), cyst‐forming nematodes Globodera rostochiensis, G. pallida (in potato), Heterodera avenae (in cereals), Ditylenchus dipsaci (in vegetables and ornamental plants) and Tylenchulus semipenetrans (in citrus). Based on observations made on samples examined at Benaki Phytopathological Institute, it was confirmed that serious infestation of new kiwi orchards with Meloidogyne spp. originated from seedlings infested at the nursery. Also the wide distribution of the nematode Tylenchulus semipenetrans in citrus orchards was mainly attributed to infested seedlings. The above observations led us, in 1985, to the decision to study the nematological fauna of nurseries in Greece.

Effects of fluoride emissions from industry on the fluoride concentration of soils and vegetation

The effects of fluoride emissions, from an aluminium reduction plant in Greece, on the concentration of fluoride in soils and natural vegetation and also the relation between injury and fluoide content of plants were investigated. Fluoride emissions from the factory caused toxicity to natural vegetation in the adjoining area. Some plant species accumulated high fluoride levels in the leaves and exhibited acute necrosis, chlorosis or both. Others did not show visible injury, in spite of their high fluoride accumulation. The intensity of symptoms changed a great deal from one individual plant to the other or even from leaves of the same plant. The average levels of fluoride in vegetation ranged from 621.2 to 257.2 ppm in severely damaged areas (zone I) and from 144.3 to 64.1 ppm in lightly damaged areas (zone III). The corresponding fluoride levels in the controls was 15.4−8.2 ppm. In soils total fluoride concentrations ranged from 823.5 to 297.6 respectively; the levels in controls ranged from 108.6 to 95.3 ppm.

Economies of scale and strategic planning for municipal waste treatment plants in Greece

More than 300 municipal waste treatment plants are expected to be built in Greece over the next 15 years at a running cost of US$360 million. From a strategic planning point of view, and considering that (1) a major portion of the cost corresponds to imported technology/equipment and (2) the financing of these plants will place a heavy burden on an already strained government budget, the following questions arise: How is the demand for various sizes of such plants expected to evolve? Are there economies of scale? Are there equity questions regarding government grants for such plants? This paper presents the findings of a research project (1987-88) whose objectives were to answer the above questions. It was found that the cost of a plant as a function of inflow is given by a simple multiplicative model with economies of scale up to 8000 m3 per day. On the basis of logical assumptions regarding the rate of increase in population and water consumption in Greece, the expected growth in demand for such plants ...

Heavy metal pollution induced by a ferro-nickel smelting plant in Greece

Seven heavy metals, Co, Cr, Cu, Fe, Mn, Ni and Zn, were measured in marine sediments, plants and invertebrates in the vicinity of a ferro-nickel smelting plant in Greece. The concentrations of metals in the sediment were higher than those found in the average unpolluted Greek coastal sediment. High levels of metals were observed in the gastropod molluscs, particularly Cerithium vulgatum, which concentrated metals more than other invertebrates.