bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potential of Energy Willow Plantations for Biological Reclamation of Soils Polluted by 137Cs and Heavy Metals, and for Control of Nutrients Leaking into Water Systems
Authors: Rodzkin Aleh , Khroustalev Boris , Kundas Semjon , Chernenok Evgenija , Krstic Borivoj 
Published: December 2019

Abstract
Willow is a low-maintenance crop that has potential for energy production and enhancing the local environment. The area of commercial plantations of willow in Europe is mostly concentrated in Sweden, with more than 20 000 ha. Willow trees are used not only for energy production, but also for reclamation of polluted soils because a plantation may grow for 20–25 years, with a three-year period of harvesting. Our research covers issues of reclamation of soils contaminated by radionuclides and heavy metals, and decreasing of eutrophication of water ecosystems with using willow plantations. The field studies of phytoremediation of soil contaminated by 137Cs by willow plants were conducted in eastern Belarus, in the area where agricultural activity was banned after Chernobyl disaster. This region is heavily polluted with 137Cs (from 185 to 555 kBq/m2) and heavy metals. The transferring factors of accumulated 137Cs and heavy metals from the soil to willow biomass were determined. The field experiments showed that willow does not accumulate actively Cd and Pb, but it accumulates Zn, Cu and Mn intensively. The potassium application decreases the accumulation of 137Cs in willow biomass and increases accumulation of Cu, Zn and Mn, but has no influence on accumulation of Cd and Pb. Our results confirmed that soils polluted with radionuclide and heavy metals could be used for willow cultivation as energy crop, if adequate management is applied. The different potential of the willow species concerning heavy metals accumulation was also established. The yield of willow biomass on polluted soils achieved 11.5–12.8 DMg ha–1 per year, depending on variety, that is competitive with the ordinary yield of willow on mineral fertile soils. Willow plantations also may be used for accumulations of nutrients like nitrogen and phosphorus in watersheds. It enables to decrease impact for water ecosystems and to control eutrophication.
CFD Modelling of Biomass Mixing in Anaerobic Digesters of Biogas Plants
Authors: Conti Fosca , Saidi Abdessamad , Goldbrunner Markus 
Published: December 2019

Abstract
Cut in greenhouse gas emissions, increment of energy from renewables and improvement in energy efficiency represent the three key targets for future energy systems. Among the available bioenergy technologies, biogas production via biodegradation and anaerobic digestion is a widely applied approach, not only to produce biofuels but also to manage industrial and domestic organic waste. Within the biogas production, a sufficient mixing of the organic mass is a crucial step to ensure high biogas yields by bacteria and enzymes. Measurements of the electric power consumption of biogas plants revealed that the electrical energy demand of the stirrer system has a high share of the total electricity consumption of a biogas plant. Investigations on real biogas digesters to optimize the mixing process are cost and time intensive. Therefore, laboratory prototypes and computational simulations represent promising alternatives to analyse and improve the efficiency of mixing systems. In this paper, a computational fluid dynamics (CFD) model is presented, which is applied to commercial stirring systems. The case of two propeller stirrers, located in diametrically opposite positions in a tank filled with ca. 1400 m3 of substrate is described in detail. For the simulation, the rheology of the fluid is adapted to a biomass with 12 wt % dry matter content and obeying the non-Newtonian generalized Ostwald-de Waele power law. The developed simulation procedure considers the rotation angle of each propeller and its height. A total of 441 mixing configurations are calculated and evaluated in terms of the technical benefit. The investigation reveals that locations of the rotors far away from the bottom and high rotational angles cause advantageous fluid dynamics.
Life Cycle Assessment of Foam Concrete Production in Latvia
Authors: Zimele Zinta , Sinka Maris , Korjakins Aleksandrs , Bajare Diana , Sahmenko Genadijs 
Published: December 2019

Abstract
Global warming being increasingly discussed, solutions for reducing emission greenhouse gases become more important in all industry sectors. The total energy consumed in the construction sector contribute up to 1/3 from all greenhouse gases emissions. Large part of it comes from the cement production – 5 % of the total global emissions. The foam concrete is lightweight concrete with good thermal properties and ability to reduce CO2 emissions by reducing the use of cement due to its low density. The aim of this study is to determine impact on the environment with the use of Life Cycle Assessment (LCA) with focus on Global Warming Potential (GWP) for two different compressive strength foam concrete mixtures produced in Latvia by unique intensive mixing technology – turbulence with cavitation effect. Afterwards, the selected foam concrete mixtures are compared with alternative materials with similar compressive strength – aerated concrete and hollow ceramic blocks. The foam concrete mixture having 12.5 MPa compressive strength showed higher CO2 emissions than hallow ceramic block. The majority of CO2 emissions comes from the Portland cement, which is a key element in its composition. On the other hand, the foam concrete mixture having 2.4 MPa compressive strength showed higher CO2 emissions than aerated concrete block. The majority of CO2 emissions are due to foam glass granules, which is the main element contributing to the increased insulation properties of the material. Comparison of each foam concrete with analogue building material by compressive strength shows that the chosen foam concrete mixtures produce greater GWP than alternative materials. This research allows to identify the environmental impacts of different foam concrete mixture components and to improve these mixtures to achieve similar properties with less impact, for example, by replacing foam glass granules with granules made from recycled glass or replacing cement with flay ash, silica fume or recycled glass powder.
Sustainable Electronic Product Development in the Baltic Sea Region: A Regional Gap Analysis of Lab Testing Services
Authors: Philipp Robert , Ozarska Alise , Prause Gunnar 
Published: December 2019

Abstract
Baltic Sea Region represents one of the most innovative areas within Europe with dominating SME sector. In order to keep the region and their product developments competitive it is necessary to safeguard access to high-tech labs including test services. This can be realized only through regional networks of universities – business cooperation. The European Union started the project “Test-4-SME” in 2017 to investigate and promote laboratory networks for testing and assessment of electronic products developed by SMEs from BSR. In a BSR wide online survey, the project consortium identified existing gaps in the regional supply of open laboratories together with shortcomings in services, expertise or test equipment, which is needed by SMEs for electronic product or devices testing. The authors take place in the “Test-4-SME” project, conducted the survey and analysed the regional demand together with the availability of labs for SME sector in the BSR. The study focusses on the research question in which BSR regions there exist already university-business networks of open labs for SME and to which extent the offered services meet the regional demand. Therefore, an approach of a gap analysis is used, which is based on primary data gathered in a BSR wide survey together with expert interviews. The results of the study are discussed in the context of the existing literature and recommendations for future improvements are highlighted.
Multi-Criteria Analysis to Select Renewable Energy Solution for District Heating System
Authors: Polikarpova Ilze , Lauka Dace , Blumberga Dagnija , Vigants Edgars 
Published: December 2019

Abstract
The research paper is focused on how to choose the most suitable renewable energy solution using multi-criteria analysis for a district heating system. Making choices is based on indicators – economic, environmental and social. In this case, the study used five indicators: resources costs, totals investments, reduction of greenhouse gas emissions, specific weight of renewable energy resources and impact on utilized land. Three situations have been compared – current situation: gas boiler, planned: solar collectors 21 595 m2 + accumulation tank 8000 m3 and alternatives: solar PV panels 5504 m2 – heat pump COP 3 are used in the estimation. The multi-criteria decision-making analysis shows that solar collectors 21 595 m2 + accumulation tank 8000 m3 are considered as the best alternative. The methodology is based on choosing a solution for a district heating company in Latvia.
Solar Energy in Low Temperature District Heating
Authors: Pakere Ieva , Blumberga Dagnija 
Published: December 2019

Abstract
Solar technologies are flexible and can be used for both centralized and decentralized energy production. The main aim of this article is to compare different solar technologies and configurations for integration into the DH system. The multi-criteria analyses method is used to rank different alternatives based on several criterions. The evaluation of criterions has been based on previous studies conducted. The multi-criteria analyses allow to compare different solar system alternatives that cannot be compared directly due to differences in their scale, type of energy produced and consumed, investment levels, etc. For the particular DH system researched, the most desirable solution is the PVT panel integration with an area of 1000 m2 which is aligned with the actual DH company’s power consumption. However, the results are strongly impacted by the assumed investment levels, efficiency of the technologies and other assumptions that could be further analysed by the help of sensitivity analyses.
Sustainability Analysis of Manufacturing Industry
Authors: Kubule Anna , Blumberga Dagnija 
Published: December 2019

Abstract
This study provides an analysis to identify the comparative sustainability of the subsectors of the manufacturing industry in Latvia. Authors assess the availability of national statistics data for the development of absolute and specific indicators, which are further used for sustainability evaluation by multi-criteria analysis, specifically the TOPSIS method. Overall eight separate indicators were used for the description of three sustainability pillars. The results provide the distribution of manufacturing sub-sectors according to their comparative sustainability, and thus the rubber and non-mineral metal manufacturing sectors and wood and wood products manufacturing are evaluated as having the lowest comparative sustainability and most appropriate for further investigation regarding the development of sector-specific energy efficiency benchmark.
Solar Facade Module for Nearly Zero Energy Building. Optimization Strategies
Authors: Sirmelis Raivis , Vanaga Ruta , Freimanis Ritvars , Blumberga Andra 
Published: December 2019

Abstract
The study presented in this paper is a continuation of small-scale passive solar wall module testing to evaluate: 1) the impact of phase change material embedded in building envelope on indoor air temperature in comparison to reference wall insulated with mineral wool 2) the impact of Fresnel lens on heat transfer processes in designed module compared to PMMA acrylic glass. Six different solar wall modules and a reference wall module were built and tested in a laboratory under controlled conditions. Compared to previous studies, changes in the experimental setup were made - solar radiation intensified, simulated outdoor temperature adjusted. The study shows explicitly the phase change melting processes in different modules tested, describing the differences between modules and impact of Fresnel lenses and insulation solutions. Room temperature with solar wall modules after the full cycle of charging and discharging latent and sensible energy (24 h) is higher than in the reference wall. Two of 3 of the proposed solar wall modules with Fresnel lens are more effective than modules with PMMA.
Analysis of Energy Supply Solutions of Dwelling Buildings
Authors: Prodanuks Toms , Veidenbergs Ivars , Kirsanovs Vladimirs , Kamenders Agris , Blumberga Dagnija 
Published: December 2019

Abstract
Individual heating consumption for dwelling buildings has an important part in Latvia’s energy balance. Increasing energy efficiency and reducing primary energy in the household sector can play a role in national energy targets. This paper analyses three different heating systems which focus on a pellet boiler and solar collector combined system. The performance of existing solar collectors is analysed and the solar collector system performance ratio is determined. Costs including investments, fuel and maintenance have been analysed and a comparison between systems is made using the indicator – costs per produced energy. Results show that the performance of the solar collector system should be increased or investments should decrease to meet the cost effectiveness of other analysed heating systems.
Empirical Model of Cost Reduction in Local DH Systems. Low Temperature Approach
Authors: Blumberga Dagnija , Gulbis Raimonds , Ievina Linda , Vitolins Valdis , Vigants Girts , Selivanovs Jevgenijs , Jaunzems Dzintars 
Published: December 2019

Abstract
Improving the efficiency of heating systems can give a tremendous contribution towards the EU energy efficiency target for 2030. Significant heat losses are one of the main disadvantages of the dominating high temperature district heating (DH). Even in summer, the high retention time of water in the network leads to thermal losses from domestic hot water reaching up to about 30 %. An empirical model based on experimental data of heat energy consumption in multi-apartment buildings is created for economical optimization of the operation of DH systems. A methodology has been developed that allows estimating the total energy cost savings (including losses) of buildings associated with the reduction of heat loss in the system, by reducing the supply flow temperature, and increasing electricity consumption by increasing the mass flow rate of water in the network.
Mechanical Behaviour of Polylactic Acid Foam as Insulation Under Increasing Temperature
Authors: Doyle Lucia , Weidlich Ingo 
Published: December 2019

Abstract
Measures to increase the share of renewables in heat generation, combined with increased energy efficiency provide a direct emissions reduction on the heating sector. Energy efficiency measures, as well as the role-out of sustainable heating technologies such as district heating networks have one key actor: insulation. However, state of the art insulating materials such as polyurethane or polystyrene have severe environmental drawbacks incompatible with today’s transition to the circular economy, and are the Achilles’ heel of the sector in terms of sustainability. Biobased and biodegradable polylactic acid (PLA) foam could be a promising replacement for fossil-based polymeric insulating foams. This study provides data on the mechanical behaviour of expanded PLA foam under different temperatures, which will help to assess its potential use as insulation where the foam is subject to heat.
Implementation of Blockchain Technology in Insurance Contracts Against Natural Hazards: A Methodological Multi-Disciplinary Approach
Authors: Pagano Andrea Jonathan , Romagnoli Francesco , Vannucci Emanuele 
Published: December 2019

Abstract
Risk insurance for disasters plays a relevant part in the implementation of risk reduction strategies during the pre-disaster phase. This is essential to support risk management towards decreasing the marginal risk allowing policy holders to transfer risk to avoid considerable financial loads from the costs incurred during the recovery phase in a post-disaster phase. There is evidence that the introduction of an integrated risk insurance strategy for community resilience planning is still lacking. Thus, this undermines the possibility to have proper optimized holistic risk management; on the one hand this strengthens pre-disaster risk mitigation measures, mostly relying on mitigative infrastructural solutions, and on the other hand it better defines risk prevention strategies mostly connected to land planning and urban development. This paper will show how insurance markets can play a key role towards mitigating the economic consequences of natural and climate change disasters, and how essential it is to better quantify the beneficial effects and costs of engineer-based mitigative solutions. In this context, the legal framework into which the actuarial quantitative model can be implemented will support the creation of an integrated multidisciplinary approach with potential implementation on a novel platform capable of collecting and processing information from different sources and dimensions such as blockchain technology. The scientific community is, in fact, increasingly interested in implementing blockchain technology to overcome problems linked to the contractual dimension of natural disaster risk insurance which can be interpreted as a sort of smart contracting. Through a study that involved four distinct areas, namely: law, environmental engineering, insurance and IT, this paper proposes a specific multidisciplinary methodology to achieve the drafting and implementation of a digital insurance contract on a blockchain platform against natural hazards. This paper proposes the basis to advance a quantitative concept to optimize the impact of catastrophe risk insurance onto the community resilience; in fact providing a key synergy for definition of pre-disaster conditions.
Is the High Quality Baukultur a Monkey Wrench in the Global Climate Challenges?
Authors: Blumberga Andra , Vanaga Ruta , Antuzs Juris , Freimanis Ritvars , Bondars Edgars , Treija Sandra 
Published: December 2019

Abstract
The EU 2030 climate package calls for raising energy efficiency, increasing usage of RES and decreasing the carbon footprint. There are stringent requirements for new buildings, but the energy efficiency potential in the existing building stock is still not fully explored. The latest trend in urban energy efficiency is the Positive Energy Block (PEB) strategies for new developments. It includes raising building energy efficiency, optimizing energy flow and implementing renewable energy sources (RES). Transforming all existing blocks in a city centre to a PEB would radically change the pattern of energy supply and consumption. European cities have historic centres with great architectural and cultural value. Any urban regeneration strategies must respect and preserve historic values. This paper describes double multi-criteria analysis evaluating urban blocks from both the energy efficiency and cultural heritage perspective with the goal to select the sample block for a “Smart urban regeneration – transition to the Positive Energy Block” case study. Proposed criteria for multi-criteria analysis to evaluate cultural heritage, liveability and energy efficiency potential describes specific qualities of the urban block. The obtained results show that blocks with higher cultural value show less energy efficiency potential and vice versa. It is recommended to apply cultural value and liveability qualities in the Smart urban regeneration process to those blocks with high energy efficiency potential.
Integration of Sun PV Electricity in Centralized Heating Systems
Authors: Delle Marta , Civcisa Iveta , Vitolins Valdis , Lauka Dace , Blumberga Dagnija 
Published: December 2019

Abstract
During the experimental research, an algorithm was developed as a guide for the introduction of solar panels (PV) in centralized heat supply (CHS) companies and a SWOT analysis of the developed algorithm action blocks was performed. SWOT analysis was carried out for a project implemented in practise and, as a result of which the centralized heat supply system uses solar power with a total capacity of 30 kW. We found that in Latvia, the areas that are suitable for solar panels are several times higher than those required by the systems. Main tasks of the work: to analyse and study available literature and information on solar PV integration into CHS; analyse available solar PV power generation equipment and technologies; develop a roadmap for easy and understandable deployment of solar panels in the company.
Paper Waste Recycling. Circular Economy Aspects
Authors: Ozola Zanda U. , Vesere Rudite , Kalnins Silvija N. , Blumberga Dagnija 
Published: December 2019

Abstract
Paper waste is a raw material for a lot of products with different added value. The engineering, economic and environmental aspects of paper waste recycling are analysed for production of composite material, cellulose nanofibers and nanocrystals, bricks with paper components, porous carbon, film of biopolymer, enzymatic sugar and bioenergy: bioethanol, hydrogen and biofuel. Through multicriteria analysis, it was possible to determine the most feasible paper waste recycling product in case of four product groups: egg packaging boxes, cardboard, reused paper, cellulose nanomaterials (nanofibers and nanocrystals). The production of cellulose nanofibres and cellulose nanocrystals has an advantage over egg packaging and cardboard production as well as reusable paper.
Tourist Transportation Generated Carbon Dioxide (CO2) Emissions in Latvia
Authors: Grizane Tamara , Jurgelane-Kaldava Inguna 
Published: December 2019

Abstract
The tourism has a close relation to the travel and tourism transport. Transport is the source of CO2 emissions. The aim of the research was to inspect the tourist transportation (TT) CO2 emissions caused by the tourist overnight trips, because any similar analysis up until now has not been made. For the determination of CO2 emissions from the TT a hybrid (top-down and bottom up) approach, correlation, regression was used. The author’s proposed algorithm for determining CO2 emissions from the TT is useful in the circumstances when there is not sufficient statistical data. In the research of regions of Latvia (NUTS 3) from 2012 to 2017, it was determined that the TT overnight trips indicated a reduction of CO2 emissions of 475 t/year. It is a positive approach in order to reach reduction of CO2 emissions according to the EU criteria for 2030; however, it left a negative impact on the national GDP. Finding solution to this economical problem is the aim of the next researches.