Effect of pyrethroid insecticides on the photosynthetic activity of pea mesophyll protoplasts

Pyrethroids are plant protecting substances whose effects on treated plants are widely monitored with often conflicting results. Field experiments showed no alteration in photosynthetic rates by a synthetic pyrethroid permethrin (Haile et al. 1999), while other studies showed an inhibition in PSII reactions by the halogen side of the molecules, and suggested QA as a target site of interaction, like in the case of urea-type herbicides (Bader and Schuler 1996). In order to clarify these opposing observations, photosynthetic effects of pyrethroids were re-tested

Preliminary studies on some chlorophyll fluorescence parameters in Crassulaceae species of different leaf characters under water stress

Chlorophyll fluorescence quenching parameters of ABSTRACT Kalanchoe daigremontiana, K. fedtschenkoi cv. marginata, K. tomentosa, Crassula multicava and Cotyledon ladysmithiensis were compared in well watered and water deficient plants. The maximum quantum yield (Fv/Fm) of photosystem II (PSII) proved to be a very stable parameter in all species and water treatments. The EQY, NPQ, qP and ETR differed in Crassula multicava from those of the other plants. The allocation of absorbed light by PSII that is utilized to photosynthetic electron transport and thermal dissipation was also calculated. Analysis of the chlorophyll fluorescence parameters demonstrated, that Crassula multicava was the only plant, which exhibited a higher proportion of excitation energy allocated to PSII photochemistry under water deficit at 1200 µmol m-2s-1 actinic light (AL) intensity

Connection between the potential wind energy and the windy days

Preliminary wind climate information are required for the selection of the sites of energetic windmeasurements. Optimal locations of wind energy projects, where the amount of utilizable windenergy can be forecasted with a good approach, can be determined using GIS and statistical methods.Anyhow, it is necessary to elaborate methods what make posible to gain data for the wind potential ofa given location on the base of measured data. Monthly number of windy days can be such predictorif its basic statistical parameters and its connection to the monthly mean wind power can bedetermined. This latter one can be substituted by the area under the curve of the function fitted to thehourly averages of the cubes of the wind speeds. A regression modell is fitted to the monthly numberof windy days and areas under the curve, on the base of time series of 7 Hungarian weather stationsand the error of the modell is determined. On this base, the modell is extrapolated to a 35 years longperiod. The area under the curve proportional to the monthly mean wind power calculated on the baseof the monthly number of windy days show a significant decreasing trend in 4 Hungarian weatherstations

A szél- és napnapenergia, valamint az energetikai célú biomassza hasznosításának éghajlati és társadalmi-gazdasági kérdései a Hernád-völgyben = Climatic conditions and social-economic issues of the utilization of wind, solar and biomass energy in the Hernád-valley, North Hungary

A kutatás során a Hernád-völgy társadalmi-gazdasági és éghajlati adottságait vizsgáltuk azzal a céllal, hogy megállapítsuk: ezek milyen mértékig segítik elő vagy gátolják a szél- és napenergia, valamint a biomassza energetikai célú hasznosítását Statisztikai források alapján feltártuk a Hernád-völgy hátrányos helyzetű településeinek legfontosabb gazdasági-társadalmi adatait, valamint az erdészeti biomasszára vonatkozó adatokat. A megyei, régiós és országos átlagadatokkal összehasonlítva többek között megállapítottuk, hogy a víz-, csatorna- és föld-gázvezetékek kiépítése jóval kedvezőtlenebb. Utóbbi kettő indokolttá teheti az energetikai fejlesztéseket. A kistáj bioenergetikai lehetőségeinél elmondható, hogy az erdészeti faapríték potenciálja feltétlenül figyelembe veendő. Statisztikai adatfeldolgozás és a térinformatikai módszerek egybekapcsolásával elvégzett vizsgálataink azt mutatják, hogy a nagy időbeli fluktuáció ellenére hatékony lehet a terület szélenergiájának felhasználása, elsősorban az alacsony indítási sebességű szélerőművek vagy a szélerőgépek esetében. A Hernád-völgy napenergia potenciáljának feltárásához a fenti két módszerrel elvégeztük a térségbe jutó, a helyi, elsősorban a domborzati körülmények által jelentősen befolyásolt globálsugárzás időbeli és térbeli eloszlásának elemzését. A felszínre érkező globálsugárzási adatok kiértékelése elengedhetetlen információkat nyújt a Hernád-völgyben tervezett napenergia beruházások tervezésénél, gazdasági elemzésénél. | Role of socio-economic and climatic endowments of the Hernád-valley in energetic solar, wind and biomass utilization have been examined in our research program. Most important socio-economic characteristics of settlements and parameters of biomass production in the Hernád-valley have been determined on the base of statistical data. Compared to county, region, or national averages water, gas and drainage systems are rather underdeveloped in the Hernád-valley. These facts support renewable energetic developments. The micro region has a good potential in chopped wood biomass. Despite its strong temporal fluctuations wind energy utilization can be effective especially in the case of low critical velocity wind turbines and windmills according to our results gained using statistical data analyses combined with geoinformatic methods. However, small windmills and wind generators with capacities of several hundred watts or kilowatts could be more effective solutions, since they can be operated in island mode, what means that their establishment requires much less permissions. The before mentioned two methods have been used for examination of solar energy potential of the Hernád-valley as well. Spatial and temporal patterns of solar irradiance strongly influenced by the relief have been determined. Amount of solar irradiance can be measured on the surface provides important information for the planning and economic analyses of solar energy utilization projects in the Hernád-valley

CONNECTION BETWEEN THE POTENTIAL WIND ENERGY AND THE WINDY DAYS

Preliminary wind climate information are required for the selection of the sites of energetic wind measurements. Optimal locations of wind energy projects, where the amount of utilizable wind energy can be forecasted with a good approach, can be determined using GIS and statistical methods. Anyhow, it is necessary to elaborate methods what make posible to gain data for the wind potential of a given location on the base of measured data. Monthly number of windy days can be such predictor if its basic statistical parameters and its connection to the monthly mean wind power can be determined. This latter one can be substituted by the area under the curve of the function fitted to thehourly averages of the cubes of the wind speeds. A regression modell is fitted to the monthly number of windy days and areas under the curve, on the base of time series of 7 Hungarian weather stations and the error of the modell is determined. On this base, the modell is extrapolated to a 35 years long period. The area under the curve proportional to the monthly mean wind power calculated on the base of the monthly number of windy days show a significant decreasing trend in 4 Hungarian weather stations