GeoRef

The historical gravity dataset of Lithuania consists of two files based on measurements carried out between 1951 and 1962: data of second and third order gravimetric network as well as data from gravity surveys. Raw data were collected by digitising the paper catalogues of gravimetric network stations and sheets of gravimetric map at a scale 1:200 000. The gravity data set covers the entire territory of Lithuania (65 000 km2). Raw data were collected by digitising the paper catalogues of gravimetric network stations and sheets of gravimetric map at a scale 1:200 000. Initially the gravity data were in Potsdam gravity system, geodetic coordinates of the gravity points – in the coordinate reference system Pulkovo 1942 (EPSG: 2499), and the heights of gravity points – in the Baltic normal height system of 1977 (EPSG code 5705). In the final countrywide set the gravity data are in the International Gravity Standardization Net of 1971 gravity system, geodetic coordinates – in European Terrestrial Reference System of 1989 coordinate reference system (EPSG:4258), and geodetic heights – in the European Vertical Reference System of 2007 (EPSG:5215). The total number of gravimetric network stations is 123, and the total number of gravity survey points is 10 660. The data were recorded into files applying DBF (Data Base Format) format. The historical gravity data set could be used for quasi-geoid modelling, for development of Earth geopotential models and for geological interpretation. Researchers will benefit in the process of evaluation and accuracy estimation of the developed products using high precision data of gravity network stations. Dataset is available at https://doi.org/10.5281/zenodo.15090241 (Šlikas et al., 2025).

The characteristics of surface plasmon polaritons at the chiroplasmabased ellipsoidal nanowire metamaterial interface are examined in this study. Surface waves have been demonstrated to possess special characteristics, such as the dispersion maps’ dependency on chiroplasma parameters such as free carrier concentration. The influence of chiroplasma features on surface plasmon polaritons characteristics are studied. This suggests surface plasmon polaritons at chiroplasma-based ellipsoidal nanowire metamaterial interface may be exploited for Plasma-on-Chip for cancer treatment.

The aim of the work was to carry out experimental research and numerical simulation of microplastic pollution in the Vilnelė River. Six locations were selected for the experimental studies: 3 measurement points and 3 releasers. It was determined that the average concentration of microplastics at the selected measurement points was in the range between 0.10 and 0.42 particles/L. The concentration of microplastics at the selected releasers ranged from 3 to 31.6 particles/L. A morphological analysis of the microplastics was also carried out. Synthetic polymer microplastics were found to be the dominant type among all detected microplastics. The ANSYS software was used for numerical modelling. The Euler–Lagrange method was selected to model the movement of microplastics in river water. It was found that microplastic pollution in the Vilnelė River was mainly lower than in other selected rivers and lakes around the world. The numerical simulation of microplastic pollution in the Vilnelė River provided models that, by depicting the pollution sources, show how far microplastic particles are transported within one hour. These models help identify the most suitable locations for further microplastic research, enable the prediction of pollution levels, and allows other researchers to repeat the research.

This paper introduces a self-calibratable absolute modular rotary encoder based on the equal division average method, designed to significantly enhance measurement accuracy and simplify installation. The proposed design integrates multiple optical sensors into the encoder stator Printed circuit board, enabling precise absolute position measurement through the averaging of sensors data. This multi-sensor approach compensates for alignment and installation inaccuracies, which are common issues in conventional modular encoders. To validate the design and predict encoder behaviour prior to manufacturing, a theoretical modelling of virtual optical sensors is performed. Based on experimentally collected cross-calibration data from a real optical encoder, this modelling framework enables to estimate the efficiency of self-calibration algorithm with sufficient accuracy and optimize the design and performance of the encoder. The obtained results confirm that the proposed measurement system significantly reduces error margin, improving the reliability and precision of position feedback. The initial position deviation of several hundreds of arcseconds might be reduced and kept below 8 arcseconds by using two or more additional optical sensors, even with the 0.5 mm misalignment of the encoder stator.

Shotcrete and compressed air are often utilised for providing temporary support in tunnel excavation. On occasions of concurrent application of shotcrete and compressed air, there would be concerns of the quality of concrete sprayed within pressurised space, as well as the strength development of shotcrete in pressurised environment. To address these concerns, field experimentation of the shotcrete strength development under compressed air pressure was conducted, and the results are reported in this paper.

In this study, the models for the DNA origami lattice will be investigated. Our aim is to theoretically explore the ways of constructing DNA origami. To achieve this goal the DNA origami structure, consisting of nanowires embedded in a host material, will be treated from the perspective of nanowire metamaterial. Surface plasmon polaritons propagating at the interface of air and DNA metamaterial are analyzed. The dispersion relation is attained using the transfer matrix technique and employing continuity conditions of electric fields and their derivatives at the boundary separating two regions. We have concluded that with numerous nanowires into the metamaterial unit, cell frequencies of surface plasmon polaritons are altered to higher frequencies. In this study, we have studied the effect of modifications of the metamaterial, allowing for the shift of the dispersion maps toward higher frequencies. It is possible to obtain the propagation of spoof plasmons mimicking the behavior of surface waves at lower frequencies. All the properties and parameters of the inorganic metamaterials are applicable to study the phenomenon of the organic substances.

The development of new sound absorbing materials and the transition to net zero emissions production have become inseparable. This paper investigates a new type of composite sound absorbing material made of waste tyre textile fibre (WTTF) and different binders: polyurethane resin (PU), polyvinyl acetate (PVA), and starch (POS). Non-acoustic and acoustic parameters were studied, and life cycle assessment was performed for the considered composite sound absorbing materials. The airflow resistivity was determined according to the ISO 9053-1 standard, while the sound absorption coefficient was determined according to the ISO 10534-2 standard, and the LCA was performed based on the ISO 14040 and ISO 14044 standards. Composite sound absorbing materials subjected to sound absorption coefficient tests showed results in the range of 0.04 to 0.99 and peaking in the frequency range of 800 to 2000 Hz, while airflow resistivity varied between 17.4 and 83.6 kPa·s/m2. The combination that gave the highest sound absorption coefficient was experimentally found to be PU composite material. Life cycle assessment results revealed that the lowest potential impact on the environment is obtained when composite materials are produced using starch as a binder and its total potential impact on the environment varied between 0.27 and 0.55 Pt, while the highest potential impact was observed by PU composites (0.33 ÷ 0.64 Pt). The results obtained experimentally and by LCA modelling revealed great attractiveness and promising development of composites using WTTF and different binders’ potential for sound absorbing applications.

The use of microalgae as a raw material for biogas production is promising. Macroalgae were mixed with cattle manure, wheat straw, and an inoculant from sewage sludge. Mixing macroalgae with co-substrates increased biogas and methane yield. The research was carried out using a three-stage bioreactor. During biogas production, the dynamics of the composition of the microbiota in the anaerobic chamber of the bioreactor was evaluated. The microbiota composition at different organic load rates (OLRs) of the bioreactor was evaluated. This study also demonstrated that in a three-stage bioreactor, a higher yield of methane in biogas was obtained compared to a single-stage bioreactor. It was found that the most active functional pathway of methane biosynthesis is PWY-6969, which proceeds via the TCA cycle V (2-oxoglutarate synthase). Microbiota composition and methane yield depended on added volatile solids (VSadded). During the research, it was found that after reducing the ORL from 2.44 to 1.09 kg VS/d, the methane yield increased from 175.2 L CH4/kg VSadded to 323.5 L CH4/kg VSadded.

A transport model usually consists of a demand model and an available transport network model. The purpose of this article is to identify the key specifics for the development of a regional public transport (PT) demand model and to point out the differences from the urban PT demand model. The traditional four-step transport planning demand model consists of trip generation, trip distribution, modal split, and assignment. This article consists of PT model development, calibration, and validation. A PTV VISUM macroscopic modeling program is used for this research. As a result, this article presents basic suggestions for how a PT demand model should be developed in regions. The presented suggestions for developing a PT demand model can be applied to any low-density region. The rest of the article is structured as follows: (1) Background: presents a literature analysis of the four-step model, modal splits, and the features of the PTV VISUM program; (2) Methods: describes the considered region of Lithuania and the data of the developed model; describes the four-step model, which is adapted to the Lithuanian region; (3) Results: presents the results and main suggestions for creating a PT demand model; and (4) Conclusions: presents the main conclusions of the study.

An ability to construct predictive models for identifying seismic oscillation parameters by using the mathematics of covariance functions and Doppler effect phenomena is examined in this work. In the calculations, the Mars seismic oscillations measurement data from InSight Mission V2, observed in the months May, June and July of 2019, was used. To analyze the observation data arrays the Doppler phenomena and the expressions of covariance functions were employed. The seismic oscillations trend's intensity vectors were assessed by least squares method, and the random errors of measurements at the stations were eliminated partially as well. The estimates of the vector's auto-covariance and cross-covariance functions were derived by altering the quantization interval on the general time scale while varying the magnitude of the seismic oscillation vector on the same time scale. To detect the mean values of z —the main parameter of Doppler expression— we developed a formula by involving the derivatives of cross-covariance functions of a single vector and algebraic sum of the relevant vectors.