Tag Archives: multi-criteria analysis

370-400 I. Berzina, S. Raita, M. Kalnins, K. Spalvins and I. Kuzmika
In search of the best technological solutions for creating edible protein-rich mutants: a multi-criteria analysis approach
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In search of the best technological solutions for creating edible protein-rich mutants: a multi-criteria analysis approach

I. Berzina*, S. Raita, M. Kalnins, K. Spalvins and I. Kuzmika

Riga Technical University, Institute of Energy Systems and Environment, Azenes street 12/1, LV 1048, Riga, Latvia
*Correspondence: Indra.Berzina@rtu.lv

Abstract:

Single-cell protein (SCP) is a promising alternative for replacing plant and animal-derived dietary proteins. SCP contains essential nutrients and high levels of essential amino acids (AA). Given the versatility of microbial strains and waste substrates that can be used as feedstocks, many variations of production processes can be explored. Improving these microorganism strains by enhancing their properties and productivity is vital to increasing SCP competitiveness. One of the options to enhance microorganism strains would be by creating mutants with better AA profiles. By using mutagenesis and AA inhibitors it should be possible the create novel strains with improved AA-producing properties. The use of AA inhibitors to promote selective pressure on SCP-producing strains is a novel concept and is not a widely explored approach, therefore, the further development of this method should be explored. This paper used a multi-criteria decision analysis method to evaluate different technological factors vital for creating protein-rich mutants. These factors are microorganism strains, agro-industrial waste substrates used as process feedstocks, AA inhibitors, and mutagenesis methods. Microorganisms Candida utilis and Bacillus subtilis showed the highest potential for being used. Molasses was the ‘closest to the ideal’ substrate to be used as feedstock for SCP production. As the most promising mutagenesis method ethyl methane sulphonate was selected. Glufosinate ammonium and methionine sulfoximine for both bacteria and fungi were identified as the best inhibitors for SCP-rich mutant selection. Identified combinations of optimal solutions for microorganisms, substrates, inhibitors, and mutagenesis techniques should be further investigated and evaluated in laboratory settings. This could help to increase SCP’s competitiveness as a sustainable protein source.

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1099–1111 N. Patel, L. Zihare, and D. Blumberga
Evaluation of bioresources validation
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Evaluation of bioresources validation

N. Patel*, L. Zihare, and D. Blumberga

Riga Technical University, Faculty of Environmental Science, Department of Environmental Protection and Heat Systems, Azenes street 12-K1, LV1048 Riga, Latvia
*Correspondence: nidhiben-arvindbhai.patel@rtu.lv

Abstract:

A major worldwide problem is the degradation of energy sources and the wide amount of waste products from industries, households, or from any other human activities. But what if both problems can be solved by one solution? Extensive data show that validation of bioresources increases the production of the value-added product. The assessment is based on a scenario approach. A vast literature review was performed, to investigate the alternative application pathways for various types of non-primary bioresources. Multicriteria analysis is considered as the current gold standard technique for bioresources valorisation and is proved for two cases. Firstly, we present tests that evaluate the performance of different pre-treatment methods in order to extract fibre from Hogweed biomass. Secondly, we assess the resilience of our approach using Multi-criteria analysis for brewers’ spent grain to find out the best value-added product. The results demonstrate the adequacy of the method for Hogweed biomass and brewers’ spent grain valorisation.

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1124-1132 I. Muizniece, V. Kazulis, L. Zihare, L. Lupkina, K. Ivanovs and D. Blumberga
Evaluation of reed biomass use for manufacturing products, taking into account environmental protection requirements
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Evaluation of reed biomass use for manufacturing products, taking into account environmental protection requirements

I. Muizniece*, V. Kazulis, L. Zihare, L. Lupkina, K. Ivanovs and D. Blumberga

Riga Technical University, Institute of Energy Systems and Environment, Azenes iela 12/1, LV-1048 Riga, Latvia
*Correspondence: indra.muizniece@rtu.lv

Abstract:

In many countries reed is considered as invasive or unnecessary plant, because it is spreading rapidly, causing decrease in biodiversity and creating unacceptable living conditions for many bird species in their natural habitats. Due to environmental considerations it is necessary to cut reed, to decrease their over exceeding growth. Reed burning or leaving for decomposition on fields, that has been practiced until now, creates additional carbon dioxide air pollution. Therefore, the question on what to do with cut reed has become vital from environmental protection perspective. In addition, this question applies to bioeconomy principles in compliance with their use in national economy, which makes it clear, that solutions for the use of reed biomass for production have to be found. But any production process can leave a negative effect on surrounding environment. Further to product production, economic motivation, possible market and availability of resources are primarily essential to see whether it is worth to produce the product at all. Therefore, reed biomass use possibilities in production have to be analysed as a complex question, taking into account environmental and climate, economic and technological aspects. In this study, solutions to perspective reed biomass use are evaluated, considering environmental protection requirements. For this task, multi-criteria analysis method TOPSIS is used, which includes 11 environmental and climate, economic and technological criteria. Evaluation includes both – already existing and new products that are divided in 3 sectors: power industry, construction and other products. Results of the research clearly state, which of reed biomass made products are perspective, taking into account not only traditional economic and technological aspects, but also environmental and climate aspects.

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155–161 T. Holota, M. Holienčinová, M. Kotus and J. Chrastina
The use of TOPSIS method in the manufacturing process of clutch plate of agricultural machinery
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The use of TOPSIS method in the manufacturing process of clutch plate of agricultural machinery

T. Holota¹*, M. Holienčinová², M. Kotus³ and J. Chrastina¹

¹Slovak University of Agriculture in Nitra, Faculty of Engineering, Department of building equipment and technology safety, Tr. A. Hlinku 2, SK 949 76 Nitra, Slovakia
²Slovak University of Agriculture in Nitra, Faculty of Economics and Management, Department of Marketing and Trade, Tr. A. Hlinku 2, SK 949 76 Nitra, Slovakia
³Slovak University of Agriculture in Nitra, Faculty of Engineering, Department of Quality and Engineering Technologies, Tr. A. Hlinku 2, SK 949 76 Nitra, Slovakia
*Correspondence: tomas.holota@gmail.com

Abstract:

Rating and determination of factors of importance affecting the pressing process of clutch plates is, in most organizations, an individual and subjective decision of individual employees.
The paper describes the process of relevant material selection for the organization. This process is designed with the aim to use the exact methods in order to replace subjective material selection by objective process. The most appropriate method appears the multi-criteria statistical analysis TOPSIS.
TOPSIS method has been widely applied in many areas with good results as the choice of marketing strategy, optimization of mechatronic systems, safety management, business competitions, management of crisis situations, assessment of trends, planning and many others. This is the first time when TOPSIS method was used in the selection of the most important causes affecting the pressing process of clutch plates.
The aim of this paper is to carry out the multi-criteria statistical analysis TOPSIS which evaluates and determines the order of importance of various factors affecting the pressing process of clutch plate which is a component part of agricultural machinery. On the basis of performed method we can prevent from subjective evaluation and make rational decisions based on the statistical analysis.

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1169–1179 V. Malijonytė,, E. Dace, F. Romagnoli and M. Gedrovics
Methodology for determining the mixing ratio of selected solid recovered fuels
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Methodology for determining the mixing ratio of selected solid recovered fuels

V. Malijonytė¹,², E. Dace¹*, F. Romagnoli¹ and M. Gedrovics¹

¹Riga Technical University, Institute of Energy Systems and Environment, Azenes 12/1, LV-1048 Riga, Latvia
²Kaunas University of Technology, Institute of Environmental Engineering, Donelaičio g.20, LT-44239 Kaunas, Lithuania
*Correspondence: elina.dace@rtu.lv

Abstract:

Energy recovery is a preferable waste management method for waste that cannot be reused or recycled. For energy recovery, various types of waste with differing properties are being used, e.g. mixed municipal solid waste or end-of-life tires. To achieve a more stable and homogeneous characteristics of the waste derived fuels (RDF, SRF), they can be mixed in a number of ratios. The paper presents a methodology for determining the optimal mixing ratio of three selected waste derived fuels (mixed municipal solid waste, sewage sludge, end-of-life tires) considering environmental and economic aspects. The developed method is based on combining life cycle assessment method, mass balance calculations and multi-criteria analysis (the technique for order of preference by similarity to ideal solution – TOPSIS). The results show that mixing the various waste derived fuels allows obtaining a more sustainable solution than in the case of each separate waste derived fuel.

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