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Found 6319 publications

Investigation of the shelf life of fruit yogurts as a function of the treatment of flavoring substances

E. Lakatos V. Kapcsándi

Publication Name: Elelmiszervizsgalati Kozlemenyek

Publication Date: 2021-01-01

Volume: 67

Issue: 1

Page Range: 3293-3314

Description:

1. SUMMARY Milk and dairy products represent one of the foundations of the human diet because of their valuable ingredients and pleasant sensory properties. The aim of our research was to investigate how different heat treatment processes (microwave irradiation, drying) affect the shelf life of dairy products (yogurt) from a microbiological point of view. In the course of our measurements, the effects of the different heat treatment parameters of the flavoring substances used in the production of the products (apples, bananas) on the microbiological properties of the products and, thus, on their shelf life were investigated. In our experiments, conventional drying (55 °C, 24 hours) and microwave irradiation technology (800 W, 55 °C, 10 min) were used as treatment forms of the additives. Comparisons were made in terms of microbiological parameters (total viable count, yeast/mold count and E. coli/coliform count). Based on our results, we believe that the drying process can ensure microbiological safety in food production if the air circulating in the equipment has adequate hygienic properties. The microwave irradiation technology can be used successfully to inhibit microbes in foods, in this case fruits. However, the same treatment parameters cannot be applied to different fruits.

Open Access: Yes

DOI: 10.52091/JFI-2021/1-3-ENG

Welding distortion generated uncertainties in the vibrational behavior of a ladder-like structure

Dániel Feszty Marcell Treszkai David Sipos

Publication Name: Proceedings of Inter Noise 2021 2021 International Congress and Exposition of Noise Control Engineering

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Recent developments in acoustic simulation methods allowed engineers to assess the vibroacoustic behavior of various type of structures within a virtual environment, thus allowing the replacement of prototype-based development with simulations. However, there are some factors, that cannot be considered in simulations in advance. In the present study, the effect of the distortions generated due to welding on a ladder-like structure equipped with flat plates was investigated. The measured acceleration frequency response functions were compared to finite element simulation results. The measured responses differed significantly from the simulation, even in the low frequency ranges, where the global modes were not expected to be altered or vanished. Investigation of the simulated results revealed that the additional modes were related to the vibration of the plates, which were assumed to be flat, instead of considering the warping caused by the welding process. After measuring the approximate deformation of the plates, an updated simulation model was made, introducing an approximate curvature in them. The results obtained with the updated simulation model performed much better in the low frequency range as well as in the third octave-averaged frequency bands up 1200 Hz. The sensitivity of the warping was also systematically evaluated.

Open Access: Yes

DOI: 10.3397/IN-2021-2844

Categories of various plant biostimulants - Mode of application and shelf-life

Heino B. Papenfus Shubhpriya Gupta Vince Ördög Karel Doležal Jeffrey Norrie Wendy A. Stirk Alan T. Critchley Johannes van Staden James F. White Manoj G. Kulkarni

Publication Name: Biostimulants for Crops from Seed Germination to Plant Development A Practical Approach

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1-60

Description:

A plant biostimulant is any substance or microorganism which can be applied to plants to enhance seed germination and plant growth development along with its nutritional efficiency. Plant biostimulants collectively influence: plant growth development, pollen tube development, flower and fruit set, plant pigments, shoot and root development, nutritional efficiency, yield and shelf-life of crops, rhizospheric and soil microorganisms, general soil health and plant-environment interactions. Biostimulants are derived from natural origins and can help reduce the use of chemical products and also mitigate the negative impacts of harmful chemicals in the environment. This chapter focuses on their modes of application and effects on crops and horticultural plants. It also emphasizes impacts on the shelf-life and efficiencies of commercial biostimulants, as compared to synthetic chemical products and highlights the opportunities and challenges of their market expansion.

Open Access: Yes

DOI: 10.1016/B978-0-12-823048-0.00018-6

Analysis of network traversal and qualification of the testing values of trajectories

Tibor Vadvári István Lakatos Krisztián Szabó András Háry Tamás Péter Ferenc Szauter

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2021-01-01

Volume: 18

Issue: 10

Page Range: 151-171

Description:

This research work is aimed directly at the study of network traversal, for the design of vehicle dynamics and driving test programs. The work can be applied more widely to the qualification of test tracks. In addition to general modelling, this method can also be used to investigate the formation of loops in order to take into account, the sub-routes, multiple times. An important area of its application is the more comprehensive analysis of complex loads, as well as, the development of learning algorithms, which can be achieved by repeating multiple traversals of certain track sections within a series of measurements, and can be used for the development of on-board vehicle systems. The mathematical modelling is presented through the application of the geometric graph and subgraphs of the track. The properties of the Markov model extracted from the connection matrix of the large-scale network model are also presented. In this way, the modelling is extended to the application of the connection matrix of the large-scale network model as well. The modelling and computational details are demonstrated by means of a computer based, algebraic program. This modelling and the results of the calculations, will allow the further development of a test program design and related evaluation methods.

Open Access: Yes

DOI: DOI not available

Efficient Design and Sustainability Assessment of Wastewater Treatment Networks using the P-graph Approach: A Tannery Waste Case Study

Ákos Orosz Kirti M. Yenkie Jean Pimentel Emmanuel A. Aboagye Heriberto Cabezas Ferenc Friedler

Publication Name: Chemical Engineering Transactions

Publication Date: 2021-01-01

Volume: 88

Issue: Unknown

Page Range: 493-498

Description:

In the tannery industry approximately, 30 - 35 m3 of wastewater (WW) is generated per ton of rawhide processed. The WW comprises high concentrations of salts, ammonia, dye, solvents, and chromium. Of particular interest is chromium, which has been proven to cause dermatological, developmental, and reproductive issues on exposure. Thus, there is a need for appropriate treatment of the tannery WW before it is discharged for natural remediation. However, designing a treatment process is multifaceted due to the availability of multiple technologies that can perform similar tasks and the complex composition of waste streams. This necessitates the treatment to be performed in stages namely, primary, secondary, and tertiary. In some cases, pretreatment is required to enhance the recovery in the following stages. Due to the combinatorial nature of this problem, the P-graph approach, which uses principles from graph theory, can be used to synthesize a treatment pathway by selecting appropriate technologies at each stage, while meeting required purity specifications. Furthermore, the P-graph approach can provide alternate feasible treatment structures ranked based on Economics as well as Sustainability indicators, such as the Sustainable Process Index (SPI). In this work, a tannery WW case study is investigated with multiple stages and treatment technologies. A complex maximal structure is generated comprising all possible technologies, flows, connections, bypasses, mixers, and splitters. The models for each technology involve capital and operating costs, efficiency, and SPI at each stage of the treatment process. This problem is formulated in P-graph and solved using the Accelerated Branch-and-Bound algorithm.

Open Access: Yes

DOI: 10.3303/CET2188082

Investigation of effect of water content on railway granular supplementary layers

Szabolcs Fischer

Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu

Publication Date: 2021-01-01

Volume: 2021

Issue: 3

Page Range: 64-68

Description:

Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different ‘samples’ were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multilevel shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road ‘products’ have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.

Open Access: Yes

DOI: 10.33271/nvngu/2021-3/064

The impact of migration of highly skilled workers on the country’s competitiveness and economic growth

Laszlo Vasa Yuriy Bilan Halyna Mishchuk Olena Oliinyk Oleksandr Akimov

Publication Name: Montenegrin Journal of Economics

Publication Date: 2021-01-01

Volume: 17

Issue: 3

Page Range: 7-19

Description:

The links between the migration of highly skilled workers and economic growth (in terms of GNI per capita) and the competitiveness of countries have been studied. The study is based on statistics from developed countries and using correlation-regression analysis and modelling, as well as cluster analysis using the package of processing and analysis of statistical information STATISTICA. The analysis found that the immigration of workers with higher education has a significant impact on strengthening the competitiveness and economic development of countries – this is confirmed by the impact of talent migration, which is assessed by the values of case studies (‘The Human Flight and Brain Drain’ sub-index Fragile States Index and ‘Brain gain’ sub-index’ in the Global Talent Competitiveness Index and ‘Highly educated workers’ sub-index in the OECD indicators of talent attractiveness). Their impact on macroeconomic indicators is higher compared to the links with social development indicators. Of course, this does not mean that such links should not be seen as important in public economic development management, as they illustrate the level of efficiency achieved in creating favourable conditions for realizing the potential of highly skilled workers, including pull-factors for their immigration. But in the macroeconomic management of a competitive economy, according to our research, actions aimed at attracting highly skilled migrants have the most significant and obvious impact. Other links can be taken into account and used in modelling for the development of institutional support for proactive migration policy for highly qualified workers.

Open Access: Yes

DOI: 10.14254/1800-5845/2021.17-3.1

Counterhegemony: Radical Economics and the Appeal of State Socialism in Cold War Era Nigeria (1946–1990)

Adam Mayer

Publication Name: International Journal of African Historical Studies

Publication Date: 2021-01-01

Volume: 54

Issue: 3

Page Range: 377-397

Description:

Normative state socialist economic theory appeared in the mid-1920s with Soviet economist Preobrazhensky. In Nigeria, many economic thinkers were influenced by Soviet and other Eastern European economic theory during the Cold War years. Bala Usman and Segun Osoba focused on the destruction of feudal land law and on delinking from the capitalist world economy; Bade Onimode and Ola Oni on emulating state socialist Eastern European economic theory and practice in an effort to overcome structural underdevelopment; Claude Ake in his Marxist phase made use of the Hungarian economist Tamás Szentes’s heterodox socialist development theory that the latter developed while the two were colleagues at the University of Dar-es-Salaam in Tanzania. Nigeria’s oil incomes were to be used in all these plans to kick-start heavy industry in the country. As the USSR’s alternative globalization path disappeared and then the Nigerian compradores’ share of profits grew by the early 21st century, interest in these radical classics reappeared in Nigeria.

Open Access: Yes

DOI: DOI not available

The impact of covid-19 on the economy and sustainable e-commerce

Laszlo Vasa Judit Oláh Nicodemus M. Kitukutha

Publication Name: Forum Scientiae Oeconomia

Publication Date: 2021-01-01

Volume: 9

Issue: 2

Page Range: 47-72

Description:

This study aims to examine the impact of COVID-19 and sustainable e-commerce in Hungary and Kenya. COVID-19 has devastated the global economy, resulting in financial and job losses. Routine changes in spending have moved the focus from non-essential to essential items, due to the impact of COVID-19, the associated economic meltdown, and the deterioration of people’s physical and mental health. However, e-commerce can be a better option to stop the spread of COVID-19 due to its real benefits and usefulness in solving the challenges faced. The methodology used in this paper is the collection of primary data from an online survey questionnaire, and secondary data from several databases,e.g.,the World Health Organisation (WHO) and Johns Hop-kins Centre websites. The results show the negative impact of COVID-19 on society and the economy, as well as the positive and significant effects ofthe growth of e-commerce during COVID-19, where most of the goods being purchased are medical supplies: masks, medicines, and food. This has been made possibleby the rise of e-commerce platforms as a link in sustainable e-commerce after the significant disruption to the worldwide supply chain due to total lockdown. E-commerce has shown growth during the COVID-19 pandemic period as a sustainable platform. In conclusion, this study proposes policies that support e-commerce in developing countries during and after COVID-19. Furthermore, theoretical, and managerial implications are proposed in the study. It is high time to warn businesses to adopt information and communications technology (ICT) to flourish and thrive during times of financial and economic hardship, such as the use of e-commerce with the right policies enacted to support sustainable e-commerce.

Open Access: Yes

DOI: 10.23762/FSO_VOL9_NO2_3