scholarly journals Comparison of the 14C activity of groundwater and recent Tufa from Karst areas in Yugoslavia and Czechoslovakia

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 884-892 ◽  
Author(s):  
Nada Horvatinčć ◽  
Dušan Srdoč ◽  
J A N Šilar ◽  
Hana Tvrdíková
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Chemical Properties ◽  
Spring Water ◽  
Geologic Structure ◽  
Recharge Area ◽  
Karst Springs ◽  
Physico Chemical ◽  
Karst Areas ◽  
Plitvice Lakes

14C activity of dissolved inorganic carbon (DIC) in water and in recent tufa samples in several karst areas of Yugoslavia and Czechoslovakia was measured. Groundwater from 11 karst springs were measured for their isotopic content (14C, 3H, 13C), chemical composition (HCO3 −, Ca2+, Mg2+) and physico-chemical properties (temperature, pH). Seasonal variations of the 14C activity of DIC in two karst springs in Plitvice Lakes area, Yugoslavia, were measured systematically from 1979 – 1987.14C activity of recent tufa samples from several locations downstream were also measured. The activity of DIC in karst spring water in both countries ranged from 63–87 pMC, which is attributed to differences in geologic structure of the recharge area, topsoil thickness and composition. Grouping of 14C activities of DIC ca (82±4)% is evident. Tritium activity at all the springs indicated short mean residence time (1–10 yr). Concentration of HCO3 −, Ca2+ and Mg2+ in spring water varied with geomorphology. 14C activity of streamwater and recent tufa increased downstream from karst springs due to the exchange between atmospheric CO2 and DIC.

scholarly journals Radiocarbon Concentration and Origin of Thermal Karst Waters in the Region of the Bükk Mountains, Northeastern Hungary

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 543-550 ◽  
Author(s):  
Ede Hertelendi ◽  
Mihály Veres ◽  
István Futó ◽  
Éva Svingor ◽  
Lajos Mikó ◽  
...  
Keyword(s):  
Thermal Water ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Karst Aquifer ◽  
Thermal Waters ◽  
Karst Water ◽  
Recharge Area ◽  
Karst Springs ◽  
Karst Waters ◽  
Karst Systems

Karst springs are abundant in Hungary, and many are thermal (temperatures >30°). As thermal springs are a significant part of Hungary's water resources, it is important to quantify their travel times in the karst systems. Thus, we chose to measure T and δ18O in the water and δ13C and 14C in dissolved inorganic carbon (DIC) in water from 50 thermal and nonthermal springs and wells in the Bükk Mountains, northeastern Hungary. Environmental isotope data confirm the karst water-flow pattern implied by earlier studies. We found the water in warm springs and boreholes to be mixtures of cold young and old thermal water. We also determined short mean-residence times for some large cold springs. The 14C activities measured in these springs indicate that the recharge area of the karst aquifer is open to the atmosphere, and atmospheric CO2 contributes to the 14C activity of these groundwaters. We observed good correlation between 14C and 3H activities and we determined negative correlations between 14C concentration and δ13C values and temperature. From the δ18O values of the oldest thermal waters, we attribute their origin to precipitation during colder temperatures than at present.

Carbon isotopes in dissolved inorganic carbon as tracers of carbon sources in karst waters of the Plitvice Lakes, Croatia

2020 ◽  
pp. SP507-2020-49 ◽  
Author(s):  
Andreja Sironić ◽  
Ines Krajcar Bronić ◽  
Nada Horvatinčić ◽  
Jadranka Barešić ◽  
Damir Borković ◽  
...  
Keyword(s):  
Carbon Isotopes ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Carbon Sources ◽  
Karst Waters ◽  
Plitvice Lakes

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

Physico-chemical properties of the rare-earth metals, scandium, and yttrium

1963 ◽  
Vol 79 (2) ◽  
pp. 263-293 ◽  
Author(s):  
E.M. Savitskii ◽  
V.F. Terekhova ◽  
O.P. Naumkin
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Chemical Properties ◽  
Physico Chemical ◽  
The Rare Earth

Physico chemical properties and gas adsorption separation characteristics of Itaya zeolite and its modified products.

1990 ◽  
Vol 39 (442) ◽  
pp. 996-1000 ◽  
Author(s):  
Ayao TAKASAKA ◽  
Hideyuki NEMOTO ◽  
Hirohiko KONO ◽  
Yoshihiro MATSUDA
Keyword(s):  
Gas Adsorption ◽  
Chemical Properties ◽  
Physico Chemical
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