The plane trajectories of spin particles in the Schwarzschild field

Plane motions of spin particles in the Schwarzschild field are investigated. Cases of parallel transport of spin tensor (PTS) and of geodesic motion (GM) as well as of the motion under additional Pirani (PC) and Dixon (DC) conditions are considered. Using these assumptions analogues of the Binnet formula are obtained. In the case of PTS and PS the stability of circular orbits the way Liapunov interprets it is examined.     

Composite methodology for interpreting sediment transport pathways from spatial trends in grain size: A case study of the Lithuanian coast

To achieve a more robust interpretation of sediment conditions and transport based on grain size, this study combines the perspectives of two different interpretation techniques that have been developed separately and applied in the literature: (i) ‘grain size trend analysis’ interprets changes between interrelated sampling sites assuming that sediment in the direction of transport should become either coarser, better sorted and more positively skewed, or finer, better sorted and more negatively skewed; and (ii) the ‘population anomalies’ method, which estimates the balance between erosion and accumulation processes at each sampling site based on individual site deviations compared with average values for grain‐size parameters in the area of interest. The simultaneous use of both approaches enables sedimentological conditions and transport alternatives to be distinguished. This improvement is necessary because site‐specific changes and general textural trends provide information that complements the strengths and weaknesses of each perspective. The methods are implemented here using two‐dimensional Geographic Information System tools and illustrated for the Lithuanian coast. Grain‐size characteristics of 712 surface samples of sandy sediments are used to interpret sediment transport pathways and predominant sedimentological conditions in the Lithuanian coastal zone. In general, coast‐parallel sediment transport dominates the entire investigation area, although wave‐induced movement perpendicular to the coastline is inferred in the shallow nearshore zone. The deepest areas offshore are characterized by sea floor erosion in the north, whereas an accumulation zone occurs in the relatively deep central part of the study area.     

Insight into variability of spring and flash flood events in Lithuania

In this research, variability of spring (from 1 March to 30 May) and flash (from 1 June to 30 November) floods in rivers of different regions was analysed. The territory of Lithuania is divided into three regions according to hydrological regime of the rivers: Western, Central, and Southeastern. The maximum river discharge data of spring and flash floods [a total of 31 water gauging stations (WGS)] were analysed. Comparison of the data of four periods (1922–2013, 1941–2013, 1961–2013, and 1991–2013) with the data of the reference period (1961–1990) was performed. Analysis included the longest discharge data set of the Nemunas River at Smalininkai WGS (1812–2013) as well. Mixed patterns of flood changes in Lithuanian rivers were detected. The analysis of flood discharges of the Nemunas River indicated that both spring and flash floods in Lithuania were getting smaller.     

IR-OSL studies of till and inter-till deposits from the Lithuanian Maritime Region

Glacial till and inter-till deposits exposed in the Lithuanian coastal region are evidence for multiple glacial advances during the Pleistocene. Stratigraphically, tills are the most important, prominent and well preserved deposits. However, despite the importance of these deposits, there is limited chronological control and it is widely debated whether they belong to one or another Pleistocene glaciation. The aim of the present study was to find features of the glacigenic tills, which allow us to temporally constrain these deposits, which are usually deemed to be undateable by luminescence methods. To achieve the goal, 15 samples from five different till beds and 12 samples from underlying sandy inter-till deposits from the same area were taken for analysis by feldspar-based IR-OSL technique. This paper presents the results, which suggest that the studied deposits, including glacial tills, are mostly of late Pleistocene age (MIS 5 and 4). We discuss analytical data obtained for these materials and implications for stratigraphic subdivision of the till-bearing deposits in the Lithuanian Maritime Region.     

Role of mysid seasonal migrations in the organic matter transfer in the Curonian Lagoon,south-eastern Baltic Sea

We investigated population dynamics, growth and feeding of an omnivorous mysid, Paramysis lacustris, performing seasonal horizontal migrations in the Curonian Lagoon. In autumn, increased predation pressure and deteriorated feeding conditions, due to zooplankton and phytoplankton decline in the open water, forces mysids to migrate to the shoreline, where large amounts of decaying submersed vegetation occur at the end of plant growth season. Using stable isotope analysis and mixing models, we evaluated relative importance of decaying submersed macrophytes, lagoon phytoplankton and mesozooplankton in the diet of mysids during this period. In September–November, mysids actively grew and produced three cohorts. Specific growth rates of adults (10.9 ± 1.9 mm) and subadults (6 ± 0.5 mm) were 3 and 9% DW d⁻¹, respectively, resulting in population somatic production of 36 g DW m⁻². Both δ¹⁵N and δ¹³C of mysids varied in concert with those in suspended and bottom particulate organic matter (POM) and mesozooplankton. The mixing models estimated that 45% of mysid diets were composed of bottom POM originated from the decaying macrophyte Potamogeton perfoliatus, 45% by suspended POM largely consisting of phytoplankton, while mesozooplankton contributed less than 10% of the diet. This diet composition differs from that in summer, when mysids rely mostly on zooplankton and phytoplankton. Therefore, mysid horizontal migrations and their ability to efficiently utilize littoral detritus improve the efficiency of macrophyte detritus transfer up the food chain and inshore/offshore habitat coupling in the Curonian Lagoon.     

The kinematic processes in solar prominences and flares and their spectral features

In this paper various models of mass motions in solar prominences and flares, such as expansion, contraction and rotation without or with depth gradients, are considered. The variation of the source function with depth is also taken into account. Under these conditions the profiles of the first Balmer lines are calculated. The various effects of mass motions on spectral lines are studied. We have established four methods for the derivation of the velocities of motions as well as their gradients from the corresponding spectral features. These methods have been preliminarily applied to observational data, mainly those of the spectra-spectroheliograph (SSHG) of the Yunnan Observatory.     

Vilnius Photometry of Red Giant Stars in the Open Cluster NGC 7789

Photoelectric Vilnius seven-color photometry is presented and analyzed for a sample of 24 red giant branch and clump stars in the open cluster NGC 7789. For each star we have determined photometric spectral type, absolute magnitude, interstellar reddening, effective temperature, metallicity, and surface gravity. From averages over the stars in the sample we find the mean reddening to the cluster E _Y−V = 0.21± 0.02 (s.d.), or E _B−V = 0.25, and the apparent distance modulus (m−M) _V = 12.21± 0.10 (s.d.), which yield a distance of 1840 pc. The mean overall metallicity is found to be [Fe/H] = −0.18± 0.09 (s.d.). The clump stars, on average, appear to be slightly more metal-rich than the other red giants, which is most probably caused by evolutionary changes of carbon and nitrogen molecular bands falling in the photometric passbands. A difference in mass between the two groups of stars has also been detected, which suggests that the clump stars might have undergone extra mass loss before reaching their core He-burning phase of evolution.     

Quantitative provenance of silt and clay within sandy deposits of the Lithuanian coastal zone (Baltic Sea)

A quantitative provenance approach is developed and in this study applied for the silt and clay fractions of sandy, coastal deposits. Mineralogical composition of 37 surface samples was determined by X-ray diffraction (XRD). Grain-size distributions were obtained by standard dry sieving and pipette techniques. The characterization of mineralogical provenance is based upon known compositional information of possible sources, logical models for mineral combinations related to regional geological provinces and processes, and geographical features of the documented mineral distribution in the area of investigation. These interpretations are further supported by results of correlation and principal component analyses of mineral varieties, grain-size parameters and bathymetric features of the area. Partitioning of source contributions specific for each site of deposition is derived by solving simultaneous equations. Then, the quantified mineral composition at the initial source is reconstructed in the SE Baltic Sea along the Lithuanian coast, exemplifying this new methodology for quantification of sediment sources. The main sources supplying sediment to the area are: 1) Sambian Peninsula to the south (erosion of Pleistocene till and “Blue Earth” Paleogene sediments), supplying 33% of fine-grained sediment on average, 2) Nemunas River, the discharge of which passes through Curonian Lagoon and supplies an average 17% of the coastal fine sediments, and 3) Pleistocene till, eroded on the sea floor in the north and at the Olando Kepur? shore cliff and contributing an average of 50% of the sediment. Although we use the mineralogy within the environmentally important fine-grained fraction, this mathematically simple approach could be used with any other parameters characterizing the identified sources. A quantification of the separate source contributions to each individual site of accumulation studied, using the stable, mineralogical components of the “sediment archive”, offers a time-integrated, net-effect reflection of the combined processes of an entire environmental system.     

PAH body burden and biomarker responses in mussels (Mytilus edulis) exposed to produced water from a North Sea oil field: laboratory and field assessments

In order to study the impact of produced water (PW) from a North Sea oil field on blue mussels (Mytilus edulis), chemical and biological markers were selected. A laboratory exposure (0.125%, 0.25% and 0.5% of PW) and a field study (6 stations 0.2-2 km from a PW discharge point) were conducted. In the laboratory study, PAH bioaccumulation increased in mussel soft tissue even at the lowest exposure dose. Micronuclei frequency demonstrated a dose-response pattern, whereas lysosomal membrane stability showed tendency towards a dose-response pattern. The same markers were assessed in the field study, biomarker analyses were consistent with the contamination level, as evaluated by mussel polycyclic aromatic hydrocarbons body burden. Overall, obtained results confirmed the value of an ecotoxicological approach for a scientifically sound characterisation of biological effects induced by offshore oilfield operational discharges.