Molecular weight distribution of humic and fulvic acids of sediments from a north Florida estuary

The molecular weight distribution of the humic and fulvic acid fractions of two sediments was determined using Amicon ultrafiltrat ion techniques. All fractions of humic substances had a molecular weight range of less than 500 to greater than 300,000. The largest component of humic acids was in the greater than 300,000 molecular weight range, whereas, the largest percentages of fulvic acids were in the less than 500 molecular weight range and the 100,000–300,000 molecular weight range. From this preliminary investigation there appears to be a qualitative relationship between the molecular weight composition of the humic substances in the sediment and the salinity of the overlying water within an estuarine environment.     

Paleoenvironmental evolution of the Paratethys in the Slovenian Basin during the Late Paleogene

Several sections from the uppermost Eocene and Oligocene of northern Slovenia have been investigated with respect to sedimentary facies, foraminiferal assemblages, stable isotopes, carbonate microfacies, and palynology. The main objective was to reconstruct the paleoenvironmental history of the Paleogene Paratethys in this region of the eastern Alpine realm. The sediments exhibit a transgressive succession beginning with conglomerates, sandstones, and mudstones of fluvial and lacustrine origin followed by carbonates and muddy marls indicating marine conditions. The foraminiferal faunal changes from brackish to shallow marine to deeper marine assemblages and the distribution of the palynofloras corroborate the sedimentological results. Microfacies analysis of the limestones shows a wide variation of shallow water, generally mud-rich facies dominated by coralline algae, foraminifera, and corals. Microfaunas adapted to low-oxygen conditions indicate temporal sluggish bottom-water circulation which can be associated with high fresh-water fluxes. These results are discussed as reflecting both the global sea-level rise during the Early Oligocene and the regional tectonic and climatic evolution.     

Spectroscopy and optical/IR photometry of the cataclysmic variable CPD-48°1577

The photometric variability of CPD-48°1577 in the optical and IR ranges is discussed. The structure and variation of prominent emission line profiles are investigated. An estimate of the distance is given.Paper presented at the Lembang-Bamberg IAU Colloquium No 80 on Double Stars: Physical Properties and Generic Relations, held at Bandung, Indonesia, 3–7 June, 1983.Based on data collected at the European Southern Observatory in Chile.     

A survey of free boundary value problems in the theory of fluid flow through porous media: variational inequality approach — Part II

A survey is presented of work done using variational inequalities in solving free-boundary problems arising in the filtration of liquids through porous materials. In 1971 Baiocchi proposed this new method for solving such problems. This method proved effective not only from the purely theoretical point of view, that is, for proving the existence and uniqueness of a solution, but also from the point of view of yielding new, simple and efficient numerical solution schemes. This new method was systematically and extensively developed by mathematicians at the Laboratory of Numerical Analysis at the National Research Centre in collaboration with the Institute of Hydraulics of the University of Pavia. The aim of this survey is to present the basic ideas of this method, its applications, and other problems to which various researchers have extended the method. Also, the paper is written in such a manner as to be understood by a more general audience other than mathematicians, who are the ones who have done the majority of work in this area.     

Sea-Spray-Generation Dependence on Wind and Wave Combinations: A Laboratory Study

Boundary-Layer Meteorology - We investigate the effects of wind–wave interactions on the surface sea-spray-generation flux. To this end, the Marine Aerosol Tunnel Experiment (MATE2019) was...     

Palaeoclimate estimates for the Middle Miocene Schrotzburg flora (S Germany): a multi-method approach

We present a detailed palaeoclimate analysis of the Middle Miocene (uppermost Badenian–lowermost Sarmatian) Schrotzburg locality in S Germany, based on the fossil macro- and micro-flora, using four different methods for the estimation of palaeoclimate parameters: the coexistence approach (CA), leaf margin analysis (LMA), the Climate-Leaf Analysis Multivariate Program (CLAMP), as well as a recently developed multivariate leaf physiognomic approach based on an European calibration dataset (ELPA). Considering results of all methods used, the following palaeoclimate estimates seem to be most likely: mean annual temperature ∼15–16°C (MAT), coldest month mean temperature ∼7°C (CMMT), warmest month mean temperature between 25 and 26°C, and mean annual precipiation ∼1,300 mm, although CMMT values may have been colder as indicated by the disappearance of the crocodile Diplocynodon and the temperature thresholds derived from modern alligators. For most palaeoclimatic parameters, estimates derived by CLAMP significantly differ from those derived by most other methods. With respect to the consistency of the results obtained by CA, LMA and ELPA, it is suggested that for the Schrotzburg locality CLAMP is probably less reliable than most other methods. A possible explanation may be attributed to the correlation between leaf physiognomy and climate as represented by the CLAMP calibration data set which is largely based on extant floras from N America and E Asia and which may be not suitable for application to the European Neogene. All physiognomic methods used here were affected by taphonomic biasses. Especially the number of taxa had a great influence on the reliability of the palaeoclimate estimates. Both multivariate leaf physiognomic approaches are less influenced by such biasses than the univariate LMA. In combination with previously published results from the European and Asian Neogene, our data suggest that during the Neogene in Eurasia CLAMP may produce temperature estimates, which are systematically too cold as compared to other evidence. This pattern, however, has to be further investigated using additional palaeofloras.Dedicated to Prof. Dr. Harald Walther, Dresden, on the occasion of his 75th birthday.     

A numerical solution of an irrigation flowfield

Two-dimensional seepage from an array of triangular channels into permeable soil underlain at a finite depth by a drain has been solved by using the Baiocchi method. The use of this approach allowed a simple formulation of the seepage problem through extension of the solution region to an a priori known region. The new problem was treated numerically by using the S.O.R. method combined with projection. This technique proved to be very accurate when compared with analytical results and efficient from a computer programming standpoint.     

A survey of free boundary value problems in the theory of fluid flow through porous media: variational inequality approach — Part I

A survey is presented of work done using variational inequalities in solving free-boundary problems arising in the filtration of liquids through porous materials. In 1971 Baiocchi proposed this new method for solving such problems. This method proved effective not only from the purely theoretical point of view, that is, for proving the existence and uniqueness of a solution, but also from the point of view of yielding new, simple and efficient numerical solution schemes. This new method was systematically and extensively developed by mathematicians at the Laboratory of Numerical Analysis at the National Research Centre in collaboration with the Institute of Hydraulics of the University of Pavia. The aim of this survey is to present the basic ideas of this method, its applications, and other problems to which various researchers have extended the method. Also, the paper is written in such a manner as to be understood by a more general audience other than mathematicians, who are the ones who have done the majority of work in this area.