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  • 1
    Publikationsdatum: 2022-06-07
    Beschreibung: A complex approach in characterisation of submarine groundwater discharge (SGD) off south-eastern Sicily comprising applications of radioactive and non-radioactive tracers, direct seepage measurements, geophysical surveys and a numerical modelling is presented. SGD fluxes in the Donnalucata boat basin were estimated by direct seepage measurements to be from 4 to 12 L s 1, which are comparable with the total SGD flux in the basin of 17 L s 1 obtained from radon measurements. The integrated SGD flux over the Donnalucata coast estimated on the basis of Ra isotopes was around 60 m3 s 1 per km of the coast. Spatial variations of SGD were observed in the Donnalucata boat basin, the average 222Rn activity concentration in seawater varied fromw0.1 kBq m 3 to 3.7 kBq m 3 showing an inverse relationship with salinity. The continuous monitoring carried out at the site closest to the coast has revealed an inverse relationship of 222Rn activity concentration on the tide. The 222Rn concentrations in seawater varied from 2.3 kBq m 3 during high tides to 4.8 kBq m 3 during low tides, thus confirming an influence of the tide on submarine groundwater discharge. Stable isotopes (d2H and d18O) showed that SGD samples consist up to 50% of groundwater. Geo-electrical measurements showed a spatial variability of the salt/ fresh water interface and its complex transformation in the coastal zone. The presented results imply that in the studied Donnalucata site there are at least two different sources of SGD, one superficial, represented by mixed fresh water and seawater, and the second one which originates in a deeper limestone aquifer.
    Beschreibung: Published
    Beschreibung: 81-101
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Submarine groundwater discharge ; Groundwater ; Seawater ; Radioactive and stable isotopes; ; Seepage measurement ; Geophysical survey ; Numerical modelling ; Mediterranean Sea ; 03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 65 (1961), S. 2105-2105 
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 49 (1980), S. 0 
    ISSN: 1399-3054
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: Abstract The effect of potassium (0,50, 100 and 200 mg/pot) was studied on growth characteristics and nitrate reductase activity in maize (Zea mays) seedlings during water stress and subsequent recovery. In irrigated plants K+ increased the rate of leaf area expansion, leading to increased leaf area per plant. Increased leaf area was associated with decreased chlorophyll content. Water stress (–15 bars) enhanced the stomatal resistance of leaves which was further accentuated by K+ application. Nitrate reductase activity rose in irrigated plants 24 h after K+ application. Subsequently, as water stress developed, K+ helped to maintain higher NR activity for the first two days. However, K+ had no effect on half life of NR in light or darkness. During recovery from stress K+ aided to maintain the higher leaf expansion rate, the chlorophyll content and the stomatal resistance. The results above are discussed in relation to the ability of K+ to maintain better growth under water stress.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Dental traumatology 7 (1991), S. 0 
    ISSN: 1600-0595
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract In this study two zinc-oxide-based root canal sealers were compared for their tissue toxic response. The sealers tested were zinc-oxide eugenol and zinc-oxide glycerine. Fifteen albino rats were used for the study and were injected subcutaneously in the preset state. The tissue response was assessed by counting the polymorphonuclear cells at Day 1, Day 7 and Day 15 of the study period. The inflammatory response was graded according to the mean polymorphonuclear counts in the five rats for each period. The results showed that the toxicity was greater for the eugenol-containing sealer and increased during the three time intervals. For the non-eugenol sealer the response was milder and reached a peak by 7 days after which it decreased.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Biology and fertility of soils 20 (1995), S. 260-262 
    ISSN: 1432-0789
    Schlagwort(e): Azospirilla ; Nitrogenase activity ; Elevated temperature ; Acetylene reduction activity ; Azospirillum brasilense ; Azospirillum lipoferum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Nitrogenase activity, nitrogenase synthesis, and the growth of four species of Azospirillum were examined at 30°C and 42°C. Azospirillum brasilense Sp 7 did not synthesize nitrogenase at 42°C nor was the enzyme stable at this temperature. In A. lipoferum 708 and A. brasilense 12S the nitrogenase activity was stable at 42°C but the synthesis of nitrogenase was reduced. In A. brasilense Sp 9 the nitrogenase activity was stable and showed the highest C2H2 reduction activity at 42°C.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Journal of thermal analysis and calorimetry 50 (1997), S. 719-726 
    ISSN: 1572-8943
    Schlagwort(e): aluminum ; carbon black ; DTA ; indium ; TG ; zinc ; zinc oxalate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Simultaneous TG-DTA units have a work station which allows plots to be made of temperature against time, as well as the conventional TG and DTA plots. These time-temperature plots and their derivatives can be used to show details of both exothermic and endothermic events. The melting behavior of zinc is used as illustrative of endothermic phase changes. Solid-solid transitions are exemplified by noting the transitions in quartz. Examples of chemical reactions being treated to temperature-time plots are the decomposition's of zinc oxalate in nitrogen (an endothermic event) and the oxidation of carbon black in air (a sustained exothermic event). This wide selection of exothermic and endothermic events serves to illustrate the details which can be drawn from any thermogravimetric plot irrespective of the other associated equipment present, which serves to reinforce the data presented in the present study.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Journal of thermal analysis and calorimetry 50 (1997), S. 525-531 
    ISSN: 1572-8943
    Schlagwort(e): activation ; carbon ; corn cobs ; SEM ; TG
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Corn cobs obtained as waste from the corn industry, were analyzed by a TG-DTA unit in an atmosphere of flowing nitrogen. The carbonaceous products so formed were then produced on a preparative scale and activated chemically using potassium hydroxide. This resulted in the formation of a carbon with a very high surface area. The active carbon produced was then examined using thermal analysis in the temperature jump mode on a thermogravimetry unit. From this data the kinetics of degradation of the active carbon was determined using zero order rate kinetics. The pore structure of the active material was also examined using SEM. TheE a for activated corn cobs was found to be 106 kJ mol−1.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 8
    ISSN: 1432-1319
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The effect of irrigation on tillering and tiller mortality in varieties of wheat (Triticum aestivum and T. durum), triticale and barley was studied under field conditions. Low temperature in the early stages of growth promoted production of tillers whereas increase in temperature during extension growth phase increased tiller mortality. More than 1000 tillers m−2 were produced with five irrigations but 40% or more died. With limited water availability tiller production was reduced but so was their mortality. Grain yield in wheat and triticale was positively correlated with productive tillers and negatively correlated with the maximum number of tillers produced in wheat and barley grown under limited irrigation conditions. Varieties with a capacity to produce fewer tillers were identified. Some of them proved more stable in yield. No correlation was found between tiller number and grain yield in the frequently irrigated treatment.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 9
    ISSN: 1432-1319
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 595-599 
    ISSN: 1572-8943
    Schlagwort(e): methyl benzoate ; perfumes ; TG
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Ingredients used in the manufacture of perfumes can be investigated by thermogravimetry. In this study the evaporation of methyl benzoate was investigated using a simultaneous TG-DTA unit. A rising temperature method of thermal analysis was used for the study. The rate of evaporation of the ingredient was calculated from a simple plot of percentage mass lossvs. time. A derivative plot of the same was used to calculate the coefficient of evaporation in a controlled atmosphere and regulated air flow rate. In a series of programmed temperature runs on the TGDTA unit it was shown that the evaporation process is zero order, and that the evaporation coefficients at each temperature can be fitted into the Arrhenius equation. The energy of activation, Eact can be calculated from the slope of the line. It was found to be 47 kJ mol−1. This value was compared and shown to approach the enthalpy of vaporization as calculated using the Troutons or Clausius Clapeyron equation
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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