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One of the major challenges of satellite altimetry (SA) is to produce accurate sea surface heights data up to the shoreline, especially in geomorphologically complex sea areas. New advanced re-tracking methods are expected to deliver better results. This study examines the achievable accuracy of Sentinel-3A (S3A) and Jason-3 (JA3) standard retrackers (Ocean and MLE4) with that of improved retrackers adapted for coastal and sea ice conditions (ALES+ SAR for S3A and ALES+ for JA3). The validation of SA data was performed by the integration of tide gauges, hydrodynamic model and high-resolution geoid model. The geoid being a key component that links the vertical reference datum of the SA with other utilized sources. The method is tested in the eastern section of Baltic Sea. The results indicate that on average reliable sea surface height (SSH) data can be obtained 2–3 km from the coastline for S3A (for both Ocean and ALES+SAR) whilst an average distance of 7–10 km for JA3 (MLE4 and ALES+) with a minimum distance of 3–4 km. In terms of accuracy, the RMSE (with respect to a corrected hydrodynamic model) of S3A ALES+ SAR and Ocean retrackers based SSH were 4–5 cm respectively, whereas with the JA3 ALES+ and MLE4 associated SSH RMSE of 6–7 cm can be achieved. The ALES+ and ALES+ SAR retrackers show SSH improvement within a range of 0.5–1 cm compared to the standard retrackers. This assessment showed that the adaptation of localized retrackers for the Baltic Sea (ALES+ and ALES+SAR) produced more valid observation closer to the coast than the standard retrackers and also improved the accuracy of SSH data.

An ordered hypergroupoid is a hypergroupoid together with a partial order such that satisfies the monotone condition. In this paper, we introduce the notion of semihypergroup actions on ordered hypergroupoids. Some results in this respect are investigated. In particular, we prove that if S is a commutative semihypergroup acting on an ordered hypergroupoid H, then there exists a commutative semihypergroup S acting on the ordered hypergroupoid ... in such a way that $H$ is embedded in H. [ABSTRACT FROM AUTHOR]

In this research, the potential use of five hard parts (otolith, scale, eye lens, dorsal spine, vertebral bone) of Rutilus kutum for populations discrimination and biomonitoring as well as their usability as biological archive in the southern Caspian Sea was investigated. Two soft tissues (muscle and liver) were also analyzed for assessment of the possible risk of consumption and use as biomonitoring tool, respectively. A total of 60 specimens were collected using beach seine from three sampling sites (adjacent to the estuaries of the rivers Sefidrud, Tajan and Grorganrud, respectively) in the Southern Caspian Sea in May 2016. In total, the levels of 13 major and trace elements in the samples (the seven soft and hard tissues) was measured using PIXE (Proton Induced X-ray Emission) and µ-PIXE methods. Minor similarities among the tissues were observed in the case of eye lens (for P, S and Zn) and liver (for Cl, Fe and K). There were no significant relationships between the elements and biological characteristics (weight, total length and standard length). Based on the results, it seems that all the studied hard parts, except for eye lens, may offer alternatives for biomonitoring of Ca, Cl, Fe, K and S in the southern Caspian Sea. Considering Sr level in otolith, no significant differences could be found between the sampling sites 2 and 3. So it can be concluded that the specimens collected from the two sites are probably from the same population. Similar results were also obtained based on the results concerning K accumulation in scale. It can be concluded that scales may provide an alternative structure to otolith for stock discrimination of R. kutum in the southern Caspian Sea. Among the 10 elements that were detectable in the muscle using the PIXE method, only in the case of four of them (i.e. Zn, Cu, Fe and Mn) maximum allowable concentrations for human consumption have been defined, which in all the cases the mean concentrations in the present study were far below the recommended limits.

In this paper, we introduce the complex (anti complex) fuzzy topological space (X, T) with complex (anti complex) gradation of openness under T-norm (C-conorm), which X is itself a T-complex (C-anti complex) fuzzy subset of a nonempty set M. We show that the set of all T-complex gradations of openness on X is a semicomplete lattice. Some example such as T-complex fuzzy subspace of ᴧRm, the exterior algebra on Rm are given. [ABSTRACT FROM AUTHOR]