Diverse metabolism of cell wall components of melting and non‐melting peach genotypes during ripening after harvest or cold storage

The mode of change in a range of physiological, physicochemical and biochemical parameters during fruit ripening between distinct peach genotypes (Prunus persica L. Batsch) after cold storage for up to 4 weeks was determined. The nectarine cultivar ‘Caldesi 2000’ was selected as a genotype with melting flesh (MF) characteristic (fruits characterized by extensive flesh softening during ripening) and the cultivar ‘Andross’ as a genotype with non‐melting flesh (NMF) characteristic (fruits characterized by limited flesh softening during ripening). Flesh firmness, ethylene production, physicochemical and biochemical properties of the cell wall were determined and significant differences between the fruits of the two genotypes were recorded. Fruits of the NMF genotype were characterized by higher tissue retention and ethylene production during their ripening, higher content of uronic acids, as well as higher capacity for calcium binding in the water‐insoluble pectin fraction compared with fruits of the MF genotype. Additionally, the ripening of MF‐type fruits was characterized by higher losses of neutral sugars, especially those of arabinose and galactose than the NMF‐type fruits and these losses were more intense after extended cold storage periods. In fruits of the NMF genotype the decreased activity of pectin methyl esterase (PME) combined with higher levels of calcium in the water‐insoluble pectin fraction possibly provided less substrate for polygalacturonase (exo‐, endo‐PG) activity and less solubility of cell wall pectin compared with fruits of the MF genotype. Overall, the data indicate the existence of a wide range of diverse metabolic pathways during fruit ripening of fresh fruits with MF and NMF characteristics. Copyright © 2005 Society of Chemical Industry     

Heavy metal characterization of CFB-derived coal fly ash

The present study investigates the heavy metal content of coal fly ash (FA) samples coming from three different sampling points (secondary cyclone, cooler and filter) of a pilot plant combustion facility. The combustion experiments were carried out in a 0.1 MW Circulated Fluidized Bed (CFB) boiler using South African coal, with the addition of limestone for sulfur capture. FA was tested for the presence of selected heavy metals using inductively coupled plasma optical emission spectrometry (ICP-OES); batch leaching tests were conducted as well. The samples were also characterized in terms of their microstructure, chemical and mineralogical composition, total surface area and particle size distribution. Most of the studied metals (Cd, Cr, Cu, Ni, Mn, Zn) showed enrichment in the fine, filter FA particles, while Pb was mostly concentrated in the cooler sample. Regarding leaching characteristics of the examined samples, Cr was found to occur in considerable amounts. Although the use of CFB technology for the combustion of solid fuels steadily gets bigger worldwide, only a very limited number of studies have environmentally assessed CFB-coal FAs to date. Thus, the current study aims to contribute toward building a more integrated knowledge on the environmental impact of this abundant power production by-product.     

Infrared spectra of some thin amorphous films of MoO3-In2O3 deposited by vacuum evaporation

The infrared absorption spectra of vacuum-evaporated MoO₃-In₂O₃ thin films are reported for a series of films of varying compositions within the spectral range 4000 to 400 cm^–1 and interpreted in relation to the spectrum of the pure MoO₃ films. The affects of changes in composition, film thickness, substrate deposition temperature and annealing on the absorption bands are observed. In some cases a shift in band frequency is also observed. The gradual increase in ordering and decrease in valency state with increase of annealing temperature is observed in the infrared curves. Some new peaks appear which reveal the presence of a lower valency state in MoO₃. The shift in band frequency may be attributed to the incorporation of Mo(VI) ions in the indium interstitial positions.     

Granulocyte colony-stimulating factor administration reverses cadmium-associated inhibition of hepatocyte regeneration

OBJECTIVE: To document whether the administration of granulocyte colony-stimulating factor (G-CSF) enhances the impaired regenerative response of hepatocytes to partial hepatectomy (PH), in cadmium-pretreated partially hepatectomized rats. MATERIALS AND METHODS: Rats were injected intraperioneally with 2.5 mg CdCl2/kg body weight, 24h before PH. G-CSF (1500 or 150 micrograms/kg body weight) or saline was administered intraperitoneally in cadmium-pretreated partially hepatectomized rats at the same time as PH. The liver regenerative process was estimated 24h after PH. [3H] thymidine incorporation into liver DNA, liver thymidine kinase (TK) activity, mitotic index and proliferating cell nuclear antigen (PCNA) immunostaining were used as indices of hepatocyte proliferation. RESULTS: G-CSF administration in cadmium-pretreated partially hepatectomized rats restored the suppressed DNA biosynthesis and TK activity (P < 0.001), to levels similar to those found in rats that were partially hepatectomized only. The mitotic index and the percentage of PCNA positive nuclei in hepatocytes were also enhanced in G-CSF administered cadmium-pretreated partially hepatectomized groups of rats. CONCLUSION: The administration of G-CSF triggers events that restore the impaired liver regeneration in this model of reduced hepatocyte proliferation.     

Marketing solar thermal technologies: strategies in Europe, experience in Greece

Solar thermal technologies (STTs) are mature in many EU Member States. However, in some EU regions solar applications, and especially the innovative ones (such as solar heating/cooling, solar drying, solar-powered desalination), remain at an early stage. The degree of development of each market does not depend on climate conditions (e.g., insolation) or on different technological developments. The major strengths, weaknesses, opportunities and threats of STTs are examined, in order to identify the most important actions that should be taken to reduce existing barriers, as opposed to RTD (Research and Technology Development) of the new STTs. These include financing schemes, publications, electronic dissemination tools, campaigns, events, creation of information centres, audits and studies.     

Assessment of pesticide residues in fresh peach samples produced under integrated crop management in an agricultural region of northern Greece

A multi-residue method using selected ion monitoring mode GC/MS has been developed for the quantitative analysis of residue levels of 23 widely used pesticides in fresh peaches produced under integrated crop management process (ICM). The proposed methodology involved a sample extraction procedure using liquid–liquid partition with acetonitrile followed by a clean-up step based on solid-phase extraction (SPE). Fortification studies were performed at different concentration levels for various types of peaches that differ in properties, such as appearance, flavor and pit. The data showed that the different peach matrices had no significant effect on recoveries. Recoveries were greater than 80% for most of the pesticides with a RSD below 18%. The limits of quantification (LOQs) were in the range 0.002–0.050 mg kg^?1, depending on the compound. To assess method performance with real samples and determine whether pesticide concentrations in peaches exceed their maximum residue levels (MRLs), the proposed method was successfully applied to the analysis of 104 fruit samples collected under integrated pest management (IPM) production during the 2006 cultivation period. Residues detected were lower than those established by legislation for all pesticides, except diazinon, where one positive sample was detected at a level of 0.03 mg kg^?1.     

An applied methodology for assessment of the sustainability of biomass district heating systems

In order to maximise the share of biomass in the energy supplying system, the designers should adopt the appropriate changes to the traditional systems and become more familiar with the design details of the biomass heating systems. The aim of this study is to present the development of methodology and its associated implementation in software that is useful for the design of biomass thermal conversion systems linked with district heating (DH) systems, taking into consideration the types of building structures and urban settlement layout around the plant. The methodology is based on a completely parametric logic, providing an impact assessment of variations in one or more technical and/or economic parameters and thus, facilitating a quick conclusion on the viability of this particular energy system. The essential energy parameters are presented and discussed for the design of biomass power and heat production system which are in connection with DH network, as well as for its environmental and economic evaluation (i.e. selectivity and viability of the relevant investment). Emphasis has been placed upon the technical parameters of biomass logistics, energy system's design, the economic details of the selected technology (integrated cogeneration combined cycle or direct combustion boiler), the DH network and peripheral equipment (thermal substations) and the greenhouse gas emissions. The purpose of this implementation is the assessment of the pertinent investment financial viability taking into account the available biomass feedstock, the economical and market conditions, and the capital/operating costs. As long as biomass resources (forest wood and cultivation products) are available and close to the settlement, disposal and transportation costs of biomass, remain low assuring the sustainability of such energy systems.     

Visual impact evaluation of a wind park in a Greek island

The visual impact of wind turbines is one of the main factors affecting public acceptance of wind parks. This paper evaluates the visual impact of a wind park in Chania, Crete, using the Spanish method of evaluation. The outcomes are combined with the psychometric testing of the residents by the use of questionnaires and with the values of the Spanish method about various scenarios concerning the size of the wind park (double, half, one wind turbine). The results of the study prove that the quantification of the potential visual impact could minimize this, apparently, main reason that affects public acceptance.