with an estimation of the mean annual flood using two approaches, i.e. the index-flood method and top-kriging. The main concept behind these methods is an estimation of the mean annual flood at ungauged locations using information taken from gauged
References Annual Reviews ( 2003 ), Homepage . Available: http://www.annualreviews.org/ . Aversa , E. S. 1985 Citation
Thermal Analysis Society’s Annual Workshop and Exhibition on May 12–13, 2010. This special issue contains a great collection of papers covering a wide range of thermal analysis and calorimetric techniques, and materials, submitted by authors from many
Facilitation by nurse plants is one of the most commonly reported interactions between plants and is regarded as an important factor in structuring plant communities. We used a meta-analysis to examine the generality of these effects, focusing on cushion plants, a common life-form occurring in high-Andean ecosystems. We targeted the following questions: (1) is there a generalized positive effect of cushions on other vascular plant species along the Andes? (2) do different species groups (i.e., annuals and perennials, natives and exotics) display different association responses to cushions? (3) does the nurse effect of cushions increase with environmental severity? Results indicated that the overall effect of cushions is positive, however these positive effects were more significant amongst exotic plants than in native plants; effects were only positive for perennial plants, and were notably negative for annuals. The positive effects of cushions also increased with physical stress, but only for perennial plants. These results allow us to suggest that as a whole cushions may be acting as keystone species that maintain the structure and diversity of high-Andean plant communities. Nevertheless, since cushions also positively affect the performance of exotic plants, we should be aware of their potential role in promoting biological invasions.
It should, in principle, be possible to date a sample without determination of annual dose rate, when two ESR centers of different stability are present. The method assumes that the centers are independent and decay according to a first order process and that their concentration is far from saturation. The model is presented with emphasis on its inherent difficulties.
Radon can accumulate in underground areas such as show caves. Repairmen and tourist guides working in such caves may thus be exposed to significant radiation doses. Therefore, it is necessary to measure the radon concentration to estimate the exact radiation dose caused by radon. Considering that the radon concentration in caves usually shows significant seasonal fluctuations, the monthly change of radon concentration was studied for 1 year in nine show caves opened to the public in Hungary. Despite the fact that all of the caves were formed in karst rocks, the annual average radon concentration levels were rather different between each other (541–8287 Bq m−3). The significant monthly fluctuation of the radon concentration indicates that the annual average radon concentration in caves can only be accurately obtained by year-long measurements.
Persicaria with 70–100 species in the world is distributed in temperate regions of both hemispheres. It has 11 species in Iran growing in moist areas and margins of rivers. Through hybridisation, plasticity and existence of overlapping habitats, species identification shows difficulty. In this study, we aimed to investigate karyotype characters and morphological features, evaluate genetic variability within and among species studied and examine species relationship using ISSR data. Nine annual taxa of Persicaria were gathered from different localities in Iran and used for studies. Our studies showed that combination of karyological, morphological and molecular data can delimit species studied. Based on karyological results, three chromosome counts (P. hydropiper (2n = 2x = 20), P. maculosa (2n = 2x = 22), P. orientalis (2n = 2x = 22)) were the first reports for the Flora of Iran. Analyses of morphological characters showed diagnostic features among taxa. STRUCTURE and AMOVA analyses showed high intraspecific genetic diversity. Our results suggested that phenotypic plasticity and hybridisation may cause genetic diversity within Persicaria species.
A 3.7 MeV external proton beam was employed to produce X-rays in Pinus rigida Mill /pitch pine/ intra-annual growth rings and several elements were quantitatively determined. The PIXE experimental set-up, rapid sample preparation methods, and some interesting observations are discussed. In addition, statistical analysis of the tree-ring element concentrations revealed that Cl, K and Ca were slightly translocated whereas the other elements detected were not. The concentrations of several elements in the rings were negatively correlated with annual stream water pH which reflected precipitation pH.
Polonium-210 was determined in 34 kinds of imported tea and 9 kinds of maté collected from the Syrian local market. The 210Po concentration was found to vary from 5.5 to 39 Bq.kg-1 and 47 to 82 Bq.kg-1 in tea and maté samples, respectively. In addition 210Po was also determined in tea and maté infusions where different infusion conditions have been examined: amount, temperature and infusion time. The results have shown that the amount of 210Po transferred from tea and maté leaves to the aqueous extract ranged from 9 to 21% and 3 to 15%, respectively. The annual intake of 210Po by Syrians due to tea consumption and maté infusions was calculated and found to be 9 Bq and 151 Bq for tea and maté, respectively: washing of maté with warm water is recommended before preparation the infusions to decrease the annual intake of 210Po.
Heating with the use of ambient energy by heat pumps is a very effective way to reduce CO2 emission. However, efficiency, economic and environmental advantages depend on the type of the heat pump and the temperature of the source, the latter usually changes during the heating season. The aim of the paper is to give the annual pattern of the COP and emission as a function of the typical source temperature pattern, moreover yearly summarized energetic and emission values are also added in the case of air source, water source and ground source heat pump systems, compared to some conventional heating mode.