Search the digital library catalog

Abstract: Efficiency of time use is a key factor in chemistry calculation tasks, affecting both, personal and professional domains. This study is dedicated to finding the fastest methods for accomplishing chemistry tasks. Our investigation delves into the comparative temporal outlays made by students as they engage three different approaches: using an electronic calculator, a basic calculator app on a smartphone, and a desktop computer calculator. As part of our research, we examine a cohort of 52 Slovenian university students, preservice teachers who were actively enrolled in chemistry and related science programs, spanning the academic years of 2019 and 2022. The results from 2019 show that students can solve the chemistry tasks most quickly using electronic calculator and take the most time to calculate the tasks using smartphones (Δmean = 133 s; ΔSD = 5 s; Δmin = 97 s; Δmax = 131 s). An even larger difference is observed from the 2022 study year (Δmean = 189 s; ΔSD = 129 s; Δmin = 170 s; Δmax = 625 s). In summary, although smartphones are recognised as a multitasking device, replacing traditional single-purpose devices, they have not been able to outperform them.
Keywords: chemistry tasks, chemistry calculations, electronic calculator, smartphones, computer calculators
Published in DKUM: 03.06.2024; Views: 140; Downloads: 20
Full text (511,50 KB)
This document has many files! More...

Abstract: NPP Krško safety analysis has been performed in such a way to allow operation with primary system average coolant temperature - Tavg inside a prescribed range, which constitute the socalled operating window. The Tavg window enables certain flexibility to select an optimum value within the Tavg range taking into account safety, operational and economical considerations. Increase of the reactor coolant temperature in general improves thermodynamic efficiency of the Pressurized Water Reactor (PWR) plant yielding to increase in the electricity production. However, higher temperature causes lower water density in the reactor core altering the neutron moderation and consequently neutron transport in the reactor. This impact on the nuclear core characteristics is investigated for the NPP Krško reactor core.
Keywords: pressurized water reactor, nuclear design calculations, reactor coolant temperature optimization, critical boron concentration, Nuclear Powe Plant Krško
Published in DKUM: 05.12.2023; Views: 332; Downloads: 28
Full text (18,06 MB)
This document has many files! More...

Abstract: SARS-CoV-2, or severe acute respiratory syndrome coronavirus 2, represents a new strain of Coronaviridae. In the closing 2019 to early 2020 months, the virus caused a global pandemic of COVID-19 disease. We performed a virtual screening study in order to identify potential inhibitors of the SARS-CoV-2 main viral protease (3CLpro or Mpro). For this purpose, we developed a novel approach using ensemble docking high-throughput virtual screening directly coupled with subsequent Linear Interaction Energy (LIE) calculations to maximize the conformational space sampling and to assess the binding affinity of identified inhibitors. A large database of small commercial compounds was prepared, and top-scoring hits were identified with two compounds singled out, namely 1-[(R)-2-(1,3-benzimidazol-2-yl)-1-pyrrolidinyl]-2-(4-methyl-1,4-diazepan-1-yl)-1-ethanone and [({(S)-1-[(1H-indol-2-yl)methyl]-3-pyrrolidinyl}methyl)amino](5-methyl-2H-pyrazol-3-yl)formaldehyde. Moreover, we obtained a favorable binding free energy of the identified compounds, and using contact analysis we confirmed their stable binding modes in the 3CLpro active site. These compounds will facilitate further 3CLpro inhibitor design.
Keywords: COVID-19, SARS-CoV-2, Mpro, 3CLpro, 3C-like protease, virtual screening, inhibitors, in silico drug design, free-energy calculations
Published in DKUM: 10.12.2020; Views: 1252; Downloads: 183
Full text (2,99 MB)

Abstract: In this paper we analyse the behaviour of the LJSEX, the main index of the Ljubljana Stock Exchange, in the period from January 2000 till May 2010. More precisely, we test for the presence of bubbles and antibubbles and try to determine whether or not a bubble could have been predicted (both the formation and the date of the bubble burst). Second, we also employ techniques used to model antibubbles to forecast the future behaviour of the LJSE index. Besides modelling index dynamics for the aforementioned period, we also seek to determine the factors that led to the bubble forming and later bursting. We find that the bubble could have been forecasted at least several months in advance. On the other hand, a very precise date of the crash seems harder to identify. By more closely analysing the interplay between interest rates, credit activity and the LJSEX, we conclude that there is a clear connection between decreasing interest rates, increased credit activity and the formation of a stock bubble. If there is a clear correlation between the early phase of a bubble and increased credit activity of the banking sector, the link between the end of the bubble and the restriction of credit activity is less pronounced. By fitting the extended antibubble model from (Johansen 1999a) we obtain the values of parameters that give us some indication of the future behaviour of the LJSEX. Based on these results we conclude that in the next few years we are likely to experience a period of increased volatility with no clear increasing or decreasing growth pattern.
Keywords: exchange, interest rate, business mathematics, calculations, models
Published in DKUM: 22.01.2018; Views: 1237; Downloads: 368
Full text (698,29 KB)
This document has many files! More...