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Buildings and Environment

Abstract

In the modern world, many cities make use of state-of-the-art technologies for a diversity of applications. A field with very specific needs is the electric power system that deals with both large entities that govern themselves (grid operators) and the citizens. For both and all actors in between, there is an increased need for information. Steps to provide these data are always taken and several initiatives are ongoing across the world to equip residential users with last generation smart meters. However, a full deployment is still not possible. Considering this aspect, the authors propose KPIs for the specific situation when some information is available from the meters and other sources, but some is not. The study case is based on a residential area occupied mainly by university students and after an extensive measurement campaign the results have been studied and analysis methods proposed.

Abstract

Mass-produced printed circuit board (PCB) electrodes were used as electrochemical cells to detect the widely-used herbicide glyphosate. Square wave voltammetry (SWV) was used to determine the presence of glyphosate in aqueous Cu(NO3)2 solution. Optimal measurement conditions for the detection of glyphosate with PCB electrodes were found. It was determined that glyphosate was able to soak into the growing plants from the substrate. Glyphosate-contaminated plant juice was distinguished from control samples using the PCB electrode. Glyphosate-contaminated plants were found to have DNA mutations.

Abstract

Heavy metal waste is very dangerous, which can change the condition of water into a solid substance that can be suspended in water and can reduce the cleanliness level of water consumed by living things. To date, heavy metals can be managed through several processes, namely physics, biology or chemistry. One of the ways to overcome heavy metal pollution is to use natural zeolite applying a co-precipitation method, as it is known that zeolite is a powerful natural material to be used for certain purposes. In order to justify the research results, several analyses have been performed, such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Surface Area Analyser (SAA), and Atomic Adsorption Spectrophotometric (AAS). From the XRD results, it has been found out that the size of each zeolite with variations in size of 150 mesh, 200 mesh, and 250 mesh is 29.274 nm, 38.665 nm and 43.863 nm, respectively. Moreover, the SEM-EDX has shown that the zeolite under consideration is a type of Na-Zeolite and that the co-precipitation method successfully removes impurity elements, namely, Fe, Ti, and Cl. The results of SAA testing have indicated that the total surface area for each variation of zeolite sizes is 63.23 m2/g, 45.14 m2/g and 59.76 m2/g. The results of the AAS test analysis have demonstrated that the optimal absorption of metal content is observed in a size of 150 mesh zeolite with adsorption power of 99.6 % for Pb metal, 98 % for Cu metal, and 96 % Zn metal.

Abstract

The European Union (hereafter – the EU) takes a strong position in the global fight against climate changes by setting ambitious targets on reduction of greenhouse gas (hereafter – GHG) emissions. A binding target is to reduce those emissions by at least 40 % below 1990 levels till 2030, which would help make Europe the first climate neutral continent by the mid-21st century. Consequently, the expected 2050 emission reduction target for the EU is 80 %–90 % below 1990 levels. The EU’s new economy decarbonisation framework – The European Green Deal – outlines and summarises Europe’s ambition to become a world’s first climate neutral continent by 2050. This supposedly can be achieved by turning climate and environmental challenges into opportunities across all policy areas and making the energy transition just and inclusive for all.

The transport, and particularly road transport, is one of the most significant fossil fuel dependent segments of national economies across the EU. Oil dependency of all segments of the transport sector makes it the single biggest source of GHG emissions in the united Europe as well. Road transport is responsible for about 73 % of total transport GHG emissions, as Europe’s more than 308.3 million road vehicles are over 90 % reliant on conventional types of oil-based fuels (diesel, gasoline etc.).

However, there is a wide range of low-emission alternative fuels for all kinds of transport that can reduce overall oil dependence of the EU’s transport sector and significantly lower GHG in road transport. Among these alternatives a tandem of the natural gas and biomethane could be named as one of the most promising for short and mid-term transport decarbonisation solutions both in the EU and Latvia.

Abstract

Nowadays the planet is facing emerging global issues related to climate change, pollution, deforestation, desertification and the number of challenges is expected to grow as the global population is forecasted to reach 10 billion margin by 2050. A concept of circular economy can have a positive contribution to the current development trajectories. In order to implement it, preferably all the energy should be produced by using renewable energy sources, but there has always been a challenge for storage of renewable energy. Therefore, considering technical and economical parameters, construction options for a pumped storage hydropower plant in Latvia have been evaluated using the desk research methodology. Results have shown that Daugavpils PSHP is the most attractive project from the technological point of view, but it requires the greatest amount of investment and construction of Daugavpils HPP. At present all the construction options for PSHP in Latvia are economically disadvantageous and would not be viable without co-financing from European or national funds. Considering both technical and economical parameters, the authors emphasise Plavinas PSHP construction option.

Abstract

The national energy and climate plans developed by the Baltic States for the period up to 2030 foresee a significant increase in the share of renewable energy in final consumption. Therefore, the development of wind, solar and distributed generation in the Baltic electricity system is expected to increase significantly in the next decade and, thus, the need for balancing capacity will increase. The planned synchronisation of the Baltic power system with the power system of Continental Europe in 2025 will also increase the need for frequency restoration and balancing reserves. At the same time, the shutdown of uncompetitive thermal power plants in the Baltics reduces centralized generation capacity. If this trend continues, the risk of electricity supply shortages will increase in the future. Therefore, it is important to identify activities that help mitigate this risk and take timely actions.

Abstract

Since 2017, the Institute of Applied Astronomy of the Russian Academy of Sciences in cooperation with the National Astronomical Observatories of the Chinese Academy of Sciences has been conducting observations of the Chang’E-3 lander carrier wave signal. The paper presents the features of observation scheduling and results of data processing. High-precision phase radar measurements have been obtained with an instrumental error of 1–2 mm. The deviation of residuals in model calculations does not exceed ± 1 cm. The estimates of CE-3 lander position have been obtained with an accuracy of 0.5’’, 7.4 m and 3.2 m in celenocentric cylindrical longitude, Px and Py coordinates, respectively.

Abstract

A project called AntArr as a new application of the DBBC3 (Digital Base Band Converter, 3rd generation) is under development. A group of antennas operating at low frequency, in the range from 10 MHz up to 1500 MHz, are phased up for VLBI, pulsar and more recently for FRB observations. Part of the scientific programme is also dedicated to SETI activities in piggy-back mode. Dedicated elements can even be added to reach still lower frequencies to observe the range down to kHz frequencies. The DBBC3 manages the array operations in a selected portion of the band and the main characteristic is to synthesize a beam with an innovative approach. The final product of the array is a single station standard VLBI data stream for correlation with other antennas, or a synthesized beam for single dish observations. A number of antennas and array prototypes are under test at a location on the Etna volcano slope, with the aim to form a complete radio telescope of up to 1024 elements in 2020 and beyond. This project completes the lower part of the frequency spectrum covered in VLBI by the BRAND EVN project. The project AntArr is hosted and financed by HAT-Lab Ltd., which is the manufacturer of the DBBC family backends.

Abstract

The present paper describes reduction procedures and imaging of radio astronomical data from the gravitational lens system CLASS B0631+519 acquired by e-MERLIN interferometer. The source has been previously imaged with VLA, MERLIN and the VLBA interferometers. Data reduction and polarisation calibration procedures will provide data on Faraday effects such as Faraday rotation and depolarization between lensed images that in turn carry information on large and small-scale magnetic fields in the lensing galaxy.

Reduction of data and imaging of the radio astronomical source have been achieved using Astronomical Image Processing System (AIPS) in conjunction with automatic data reduction pipelines that performed specific data processing steps. As a result, the sky map for the gravitational lens system has been successfully acquired and accuracy comparing the generated map to sky maps of the source produced by different authors has been confirmed.