<abstract><title style='display:none'>Abstract</title>Formaldehyde is a toxic chemical commonly found in the environment. Owing to its increased usage, its incidence has also increased, and there is a need to determine the concentration of formaldehyde for the pollution control purposes. In general, spectrophotometric methods are easy to perform, low-cost, selective and sensitive, but every spectrophotometric method has its advantages and disadvantages, which are an important factor when selecting the method for determination of formaldehyde. Therefore, the aim of the research described in this paper was to compare the current spectrophotometric methods and to summarize their advantages and disadvantages.</abstract>

Review of Spectrophotometric Methods for Determination of Formaldehyde

<abstract><title style='display:none'>Abstract</title>Coffee is one of the most valuable primary products in the world trade, and also a central and popular part of our culture. However, coffees production generate a lot of coffee wastes and by-products, which, on the one hand, could be used for more applications (sorbent for the removal of heavy metals and dyes from aqueous solutions, production of fuel pellets or briquettes, substrate for biogas, bioethanol or biodiesel production, composting material, production of reusable cups, substrat for mushroom production, source of natural phenolic antioxidants etc.), but, on the other hand, it could be a source of severe contamination posing a serious environmental problem. In this paper, we present an overview of utilising the waste from coffee production.</abstract>

Review: Utilization of Waste From Coffee Production

<abstract><title style='display:none'>Abstract</title>Production of biofuel from renewable sources is considered to be one of the most sustainable alternatives to petroleum sourced fuels. Biofuels are also viable means of environmental and economic sustainability. Biofuels are divided into four generations, depending on the type of biomass used for biofuels production. At present, microalgae are presented as an ideal third generation biofuel feedstock because of their rapid growth rate. They also do not compete with food or feed crops, and can be produced on non-arable land. Cultivation conditions (temperature, pH, light, nutrient quantity and quality, salinity, aerating) are the major factors that influence photosynthesis activity and behaviour of the microalgae growth rate. In this paper, we present an overview about the effect of cultivation conditions on microalgae growth.</abstract>

Cultivation Of Microalgae <italic>(Chlorella vulgaris)</italic> For Biodiesel Production

<abstract><title style='display:none'>Abstract</title>The residue after brewing the spent coffee grounds is an oil-containing waste material having a potential of being used as biodiesel feedstock. Biodiesel production from the waste coffee grounds oil involves collection and transportation of coffee residue, drying, oil extraction, and finally production of biodiesel. Different methods of oil extraction with organic solvents under different conditions show significant differences in the extraction yields. In the manufacturing of biodiesel from coffee oil, the level of reaction completion strongly depends on the quality of the feedstock oil. This paper presents an overview of oil extraction and a method of biodiesel production from spent coffee grounds.</abstract>

Biodiesel Production from Spent Coffee Grounds

<abstract><title style='display:none'>Abstract</title> The aim of this contribution is to compare two common techniques for determining the concentrations of nitrate, nitrite, ammonium and phosphates in surface water and groundwater. Excess of these nutrients in water can directly affect human health (e.g. methemoglobinaemia) or indirectly through the products of secondary pollution - eutrophication (e.g. cyanotoxins, emanation of hydrogen sulphide, mercaptanes, methane...). Negative impact of nutrients excess in surface water often causes the destruction of water ecosystems, and therefore, common substances of these elements must be monitored and managed. For these experiments two spectrophotometric techniques - ultraviolet spectrophotometry and nutrient photometry were used. These techniques are commonly used for quick and simple analyses of nutrients in waste water. There are calibration curves for each nutrient and for determination of their concentration.</abstract>

Comparison of Two Spectrophotometric Techniques for Nutrients Analyses in Water Samples

<abstract><title style='display:none'>Abstract</title>The paper deals with the design of replaceable jaws on pneumatics gripper of the CNC milling machine EMCO Concept MILL 105, which is part of the iCIM 3000 manufacturing and assembly system. When designing replaceable jaws to allow firm and safe clamping of rotating and non-rotating parts, it was based on limiting factors such as parameters of the pneumatics gripper, dimensions, shape and material of the clamped parts and the like.</abstract>

Estimation of Conditions in Exchangeable Jaws Design of Pneumatics Gripper

<abstract>
<title style='display:none'>Abstract</title>
The aim of the work is to indicate the direction of development of postal services by means of various analyses. According to the trend of recent years, the number of letters in domestic and international traffic keeps decreasing, while the number of parcels keeps increasing. The Universal Postal Union and the postal organizations of individual countries must respond to this trend. Of course, the Covid-19 pandemic, the complex geopolitical situation in Eastern Europe and the current energy crisis have had a significant impact on postal services. The analysis includes the EU member states, Schengen countries and Balkan countries. Indicators like average area covered by a permanent office and average number of inhabitants served by a permanent are analyzed. The comparative analysis of postal services in Serbia and Slovakia includes the number of letter, parcel and express services, revenues from these services and data on the coverage of the postal network in these countries. With the help of the analysis performed in this paper, a good example can be found and a way for further development in the functioning of the postal market and the provision of postal services. For example: new parcel services must be introduced, delivery times must be shortened, and the sending and receiving of parcels must be facilitated.
</abstract>

Analysis of the Development of Postal Services in European Countries, with a Special Focus on Serbia and Slovakia

<abstract>
<title style='display:none'>Abstract</title>
The aim of this paper is to describe characteristics of agile manufacturing and analyse the needs and benefits of agile manufacturing under the conditions of uncertainty and market turbulence. It also describes four main changes in the production environment which were implemented thanks to agile methods, and compares the lean and agile manufacturing, while describing their intersections and differences in achieving the set goals. The conclusion summarises the advantages and identified benefits suitable for organizations after implementation of agile manufacturing, as those are the important facts that can play a significant role in the survival and re-establishment of balance in the periods of uncertainty.
</abstract>

Agile Manufacturing vs. Lean Manufacturing

<abstract>
<title style='display:none'>Abstract</title>
The effects of sustainability reporting on earnings management was examined in the study extensively. Causal research design was employed in this study. The study population comprises of all the 112 quoted non-financial firms in Nigeria, sample size is 22 listed manufacturing firms purposively selected for the purpose of this study. The study covered 7 years’ period ranging from 2015-2021. The data used for this study were gotten from the annual reports and sustainability reports of the selected firms. Data used for this study were analyzed with the use of descriptive statistics and panel regression analysis. Sustainability reporting was measured in this study by using the social, economic and environmental disclosures index, whereas earnings management was measured using discretionary accrual and real earning. The outcome of the analysis of the study revealed that sustainability reporting has a significant negative effect on discretionary accruals and real earnings evidenced by t-statistics = (-2.31, -2.54, -2.95) and p-values of (0.037, 0.018 and 0.023) respectively for social, environmental and economic report disclosures on discretionary accruals and t-statistics of = (-2.53, -2.23, -2.86) and p-values of (0.012, 0.029 and 0.005) respectively for social, environmental and economic report disclosures on real earnings. The study concludes that the firms with low sustainability disclosure will probably be more involved in earnings management practices than the firms who actively disclosed their sustainability matters in details. The study recommends that firms should ensure they disclose in details the true state of their sustainability activities.
</abstract>

Sustainability Reporting and Earnings Management of Listed Non-Financial Firms in Nigeria

<abstract>
<title style='display:none'>Abstract</title>
Diversity of labour market is currently one of its most striking features. The processes of globalisation and interdependence are creating pressure for ever more international cooperation, which naturally causes more frequent clashes between the diverse elements of the environment, and increases the interdependence of economies. In this context, the COVID-19 pandemic has generally weakened existing global relationships and chains. Economies have been distorted by various types of restrictive and later stimulus measures in a relatively short period of time - a situation that leads naturally to the idea of the interconnectedness of existing processes and the labour market. The main objective of the present study was to make a comparison of the authors' views on the development of these indicators on the basis of the results of analyses of selected macroeconomic indicators, and to establish the dependence between the development of the COVID-19 pandemic, macroeconomic developments and state interventions in the functioning of economies. We begin the empirical part by analysing the evolution of quarterly GDP values in selected economies of the world, and then turn to the employment rate. We conclude the study with the evolution of unemployment in comparison with the evolution of the pandemic situation in the Slovak Republic. The comparison of selected indicators and its results confirm the existence of links between pandemic, macroeconomic and legislative developments in the Slovak Republic. Although the COVID-19 pandemic is the ultimate cause of changes in the labour market, the immediate cause of the dynamics of GDP, employment and unemployment is the state intervention in the economy.
</abstract>

The Impact of the Covid-19 Pandemic on Labour Market Diversity

<abstract>
<title style='display:none'>Abstract</title>
Germany is considered in literature to be a cradle of the 4th Industrial Revolution. Industry 4.0 has been topical and awidely accepted term worldwide. Countries at the forefront of industrial development have invested significant resources in research, development and strategic initiatives to introduce Industry 4.0 technologies. On the tenth anniversary of the launch of Industry 4.0, the European Commission developed and published the Principles for the Industry 5.0 Strategy, which will lay the foundations for further economic and industrial development. The article presents the results of research based on a critical analysis of the literature and surveys, conducted among representatives of German society.
</abstract>

Dehumanization and Humanization in the Context of Industry 4.0 and Industry 5.0

<abstract>
<title style='display:none'>Abstract</title>
The article deal with the problem of choosing an effective software tool for developing virtual trainings. The Ella platform as an innovative solution for creating of virtual training is presented. In the introductory part of the article, the Ella platform is presented as the result of our development. Ella is an integrated software ecosystem as a basis of multiple software applications focusing on the design and analysis of internal e.g. logistics, monitoring, and simulation of automotive logistics assets, and safety systems, etc. This article is focused on virtual training using the Ella platform. Furthermore, the article provides an example of virtual training that has already been carried out, with the Ella platform used in the preparation.
</abstract>

Virtual Training for Effective Education of Employees

<abstract><title style='display:none'>Abstract</title>In this paper, we present the impact of the data normalization on the classification model performance. In first part of this paper, we present the structure of our dataset, where we discuss the features of the data set and basic statistical analysis of the data. In this research, we worked with the medical data about the patients with the Parkinson disease. In second part of this paper, we present the process of data normalization and the impact of scaling data on the classification model performance. In this research, we used the XGBoost model as our classification model. The main classification task was to classify whether the patient is ill with Parkinson disease or not. Since the data set contains more numerical parameters of different scaling, the main aim of this paper was to investigate the impact of the data normalization (scaling) on the performance of the classification model.</abstract>

Impact of Data Normalization on Classification Model Accuracy

<abstract><title style='display:none'>Abstract</title>The degradation of the environment which is due to the discharge of polluting wastewater from industrial sources poses a real problem in several countries. Textile industries use large volumes of water in their operations, discharging thus large volume of wastewater into the environment, most of which is untreated. The wastewater contains a variety of chemicals from various stages of process operations, including desizing, scouring, bleaching and dyeing. The main purpose of this paper is to introduce Infrared Spectrometry with Fourier transformation as a non-destructive method for study, identifation and rapid determination of selected representatives of cationic (Methylene Blue), azo (Congo Red, Eriochrome Black T) and nitroso (Naphthol Green B) dyes. In conjunction with the ATR technique, FTIR offers a reliable detection method of dyes without extraction by other dangerous substances.Spectral interpretation of dye spectra revealed valuable information about the identification and characterization of each group of dyes.</abstract>

Usage of FTIR-ATR as Non-Destructive Analysis of Selected Toxic Dyes

<abstract><title style='display:none'>Abstract</title>Nowadays, the whole world is talking about the corona virus. The world economy has slowed down, large businesses and small businesses as well as private ones struggle to survive. The current situation will affect the lives of all of us. How can we handle this situation? How does business flexibility help us? How can we use modern technology to restore the functioning of the economy? How can losses be reduced? In this paper, we are trying to find answers to these issues. To search for answers, we used the publications of renowned experts. We summarized the overview of their views of this important issue.</abstract>

Covid-19 and Industry 4.0

<abstract><title style='display:none'>Abstract</title>Fourier transform infrared (FTIR) spectroscopy was used in this study to identify and determine spectral features of Chromochloris zofingiensis (Dönz) Fucíková et L.A. Lewis (SAG 211-14, Gottingen, Germany), Acutodesmus obliguus (Turpin) Hegewald (SAG 276-1, Gottingen, Germany) and Chlorella sorokiniana (K. Brandt) Pröschold et Darienko (SAG 211-40c, Gottingen, Germany). Polysaccharides and lipids from these three algae species were determined using Fourier Transformed Infrared Spectroscopy (FTIR) with ATR accessory with diamante crystal in spectral range from 400 – 4000 cm−1 and resolution 4.</abstract>

Characterisation Of Polysacharides And Lipids From Selected Green Algae Species By FTIR-ATR Spectroscopy

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Research Papers Faculty of Materials Science and Technology Slovak University of Technology

The Journal of Slovak University of Technology

 Research Papers Faculty of Materials Science and Technology Slovak University of Technology is a scientific journal issued twice a year. Scientific journal presenting research...

 Research Papers Faculty of Materials Science and Technology Slovak University of Technology is a scientific journal issued twice a year....