Background: The scientific researchers have the role of interacting through published articles in scientific journals or presentations at scientific and professional conferences were they can affect the practices that can make achievements to society and country. or worldwide. For this reason, scientists are encouraged after completing the project and finalizing their research investigation to publish scientific work outcomes in professional and scientific journals. Objective: The aim of this article was to describe scientometric and bibliometric indexes and explaine its importance for its evaluation and measuring quality assessment of published papers in scientific journals deposited in scientific indexed databases. Also, author criticaly analized advantages and disadvantages of current bibliometric portals for creating the list of universities and its accademic staff by counts of deposited articles in databases and number of its citations. Methods: The author searched the most influential online databases and analyzed deposited papers by scientometric/bibliometric indexes, and used a descriptive method to review important facts about scientometrics experiences in scientific and academic practice. The author used facts deposited on the main international portals for analyzing number of citations of deposited scientific papers on Scopus and Google Scholar platform - h-Index and i10-Index and number of citations as basic data fot created top list of most citated scientists in almost of all countries in the world. . Results and Discussion: Bibliometric methods are used for quantitative analysis of written materials. Citation provides guidelines for scientific work because it stimulates scientists to deal with the most current research areas and organizes scientific articles at the world level or shapes and directs them. Citation is influenced by: article quality, understanding of the article, language in which the article is written, loyalty to a group of researchers, article type, etc. Some indicators used in evaluating scientific work are Impact factor (IF); Citation of the article; Journal citations; Number and order of authors, etc. The index factor of influence depends on the quality of the journal, the language in which it was printed, the area it covers, and the journal distribution system. Finaly, three portals and its plaforms (Webometrics, "AD Scientific Index" and Stanford Bibliometric List) are not fully relevant for measuring quality assessment of universities and its academic staff, even as potentialy members of academies of sciences, like it used in the past. They need to improve in the future. In this article, we pointed out that h-Index and Google Scholar indexes for present valuable measures to determine scientific excellence. These criteria should be necessary for quality assessment of the scientific curriculum of scientists and their published papers in journals when experts of indexed databases like Medline, PMC, Scopus, etc., do reviews during the evaluation of applied journals for potentially including indexed databases. Conclusion: Current academies and academicians can propose criteria how improve indexing scientific papers with the consultation of scientific bodies and experts at universities in one country, selected regions, or worldwide. Only quality research with exact results offers the scientific community new information about the examined problem and the researcher’s personal satisfaction, and opening opportunities to receive critical reviews of those who have insight into the research.

Energy has an effective role in economic growth and development of societies. This paper is studying the impact of climate factors on performance of solar power plant using machine learning techniques for underlying relationship among factors that impact solar energy production and for forecasting monthly energy production. In this context this work provides two machine learning methods: Artificial Neural Network (ANN) for forecasting energy production and Decision Tree (DC) useful in understanding the relationships in energy production data. Both structures have horizontal irradiation, sunlight duration, average monthly air temperature, average maximal air temperature, average minimal air temperature and average monthly wind speed as inputs parameters and the energy production as output. Results have shown that used machine learning models perform effectively, ANN predicted the energy production of the PV power plant with a correlation coefficient (R) higher than 0.97. The results can help stakeholders in determining energy policy planning in order to overcome uncertainties associated with renewable energy resources.

It is known that the temperature of crystallization during the synthesis of zeolite is one of the most important process parameters. However, during the research work on the synthesis of zeolite 13X and the introduction of this material into regular industrial production, it was noticed that the heating rate of the starting reaction suspension can have an equally important influence. This influence can be so pronounced that a difference of just a few minutes in reaching the crystallization temperature can make a significant difference in product quality, affect the presence of other phases in the crystal, or even determine the direction of zeolite crystallization. Therefore, the aim of this work was to show the influence of the heating rate on the quality of the obtained 13X zeolite powders. The obtained samples were analysed in terms of crystallinity (by X-ray diffraction), chemical composition, granulometry and specific surface area (by Brunauer-Emmett-Teller analysis), and regarding water and CO2 adsorption capacities. Additionally, scanning electron microscopy analysis of the samples showed the morphological characteristics of different 13X zeolite powders. The analysis results of the obtained powders confirmed the influence of the heating rate and helped to define the optimal synthesis parameters i.e. the initial temperature and heating time, that resulted in stable product quality.

This paper presents research on hydrodynamics and mass transfer in a packed absorption column. Experimental data on dry column pressure drop, flooding point, and efficiency of absorption of CO2 in water is obtained on a lab-scale absorption column packed with Raschig rings. Auxiliary parts of equipment together with chemical analyses provide simple monitoring and collecting the data. All obtained data were used to test different mathematical models for a given problem, i.e. for determination of the dry column pressure drop, flooding point and the overall gas transfer unit height. For dry column pressure drop, models developed primarily for packed columns described the data the best, with the Billet model generating a 6.54 % mean error, followed by Mackowiak and Stichlmair models. In flooding point calculations, empirical models were tested and models of Lobo, Leva and Takahshi gave the best results. Mass transfer (absorption) experiments gave expected results, since absorption efficiency increased with the increase in the liquid/gas flow rate ratio, i.e. with approaching the flooding point. The Onda?s model was used to calculate partial mass transfer coefficients in liquid and gas phases based on which the height of the overall gas transfer unit was estimated and subsequently compared with the experimental data. Deviation of calculated and experimental results for the height of the overall gas transfer unit is in the expected range of 0-20 %, with mean value of 15.5 %. In conclusion, the available models for determination of the investigated hydrodynamics and mass transfer parameters in packed absorption columns gave adequate results in comparison to the experimental values.

With the increasing participation of renewable energy sources in the production of electricity, the answer to the question of the necessary operating reserve capacity in power systems is becoming more and more complicated. The very fact of the variability of driving energy (sun, wind, water) in photovoltaic power plants, wind power plants and small hydropower plants makes the required operating reserve capacity variable. As the electric power system itself is stochastic, the inclusion of renewable energy sources in the operation of electric power systems emphasizes its stochastic characteristic even more. For this reason, the need for operating reserve in electric power systems from the aspect of renewable energy sources and with them in connection with micro-grids, is best solved using the tools of probability, that is, statistics and estimation. The issue of operating reserve in the power system was investigated by Bayesian statistics, which connects the simultaneous occurrence of a random variable (available capacity of renewable energy sources in micro-grids) with a statistical variable (load in micro-grids). The result of this research is the probability of a deficit or surplus of available energy in micro-grids, and the consequence of that probability is the probability of the need and degree of engagement of the operating reserve in the power system using system’s thermal electric power plants and/or hydro electric power plants.

Welded structures place increasing demands on the level of increased resistance to fracture. A large number of fractures of welded structures, which occur during exploitation at a stress level below of the allowable, indicates the danger of brittle fracture. The assessment of brittle fracture susceptibility was analyzed by testing Sharpy specimens, and the total impact energy, components of total impact energy (crack energy initiation and crack energy propagation) were used as parameters in the analysis.

Multi-material design was developed as a modern design concept for lightweight structures (Lightweight design - LW) which aims to integrate different types of materials into one structure. The main problem when joining sheets made of different, i.e. dissimilar materials, primarily steel and aluminum alloys, are the different mechanical, physical and chemical properties of the materials being joined. Through this paper, the state of the art will be analyzed when it comes to modern technologies for joining steel and aluminum alloys sheets. The term "modern joining technique" refers to all innovative joining technologies that have been developed or have seen significant application in the last few years.