Commutators in Completely Simple Semigroups

We obtain a characterization of the binary commutator on completely simple semigroups, using their Rees matrix representation. Consequently, we prove that a regular semigroup is nilpotent (solvable) if and only if it is simple, and all its $\mathcal{H}$-classes are nilpotent (solvable) groups

Exploring trends in environmental pollution and hazardous chemical waste reporting

In contemporary society, environmental pollution and hazardous chemical waste are pressing concerns. This study investigates reporting trends related to environmental pollution and hazardous chemical waste in twelve scientific journals and daily newspapers. Notably, we found that the year 2013 marked a significant peak with the highest number of articles on these topics. Understanding the publishing and reporting trends of these subjects is pivotal for informed public education and underscores the significant influence of scientific research in shaping media reporting. As the global community faces increasing environmental challenges, accurate and scientific-based reporting is essential for fostering public awareness and facilitating effective solutions

The use of metaphor in the language of Italian sports' commentators ; Использование метафор в речи итальянских спортивных комментаторов ; L'uso della metafora nel discorso dei telecronisti sportivi italiani

У дисертацији се под окриљем литературе посвећене метафори и метонимији, а посебно кроз призму изучавања метафоре у конверзацији, испитује присуство метафоре у говору италијанских спортских коментатора. Присуство метафоре истражено је на три начина. Испитано је који су метафорички концепти присутни, затим које су фреквенција и густина употребе метафоре, те у којој мери је у говору италијанских спортских коментатора присутна спортска метафора. Такође је истражено у којој мери је говор италијанских спортских коментатора сличан свакодневном, неформалном говору...Under the guidance of literature dedicated to metaphors and metonymy, and especially through the prism of the study of metaphors in conversation, in this dissertation we have examined the presence of metaphors in the speech of Italian sports commentators. The presence of metaphor was investigated in three ways. We have examined which metaphorical concepts are used, what the frequency and density of the use of metaphors are, and to what extent is the sport metaphor present in the speech of Italian sports commentators. It has also been explored to what extent the speech of Italian sports commentators is similar to everyday, informal speech..

A review of the process of trafficking in human beings

Trgovina ljudima sa sobom nosi značajne društvene rizike, često je oblik organizovanog kriminaliteta, njome se krše osnovna ljudska prava, značajan je uzrok korupcije, pranja novca, ilegalnog rada, izaziva demografsku destabilizaciju, migracione procese, jednom rečju predstavlja veliko društveno zlo. S obzirom na činjenicu da trgovina ljudima predstavlja veoma težak zločin protiv dobara zaštićenih međunarodnim pravom, svrsishodno je, između ostalog, ukazati na to da je u pitanju čitav proces, koji uglavnom započinje željom žrtve da napusti svoju zemlju, bez određenih predstava o tome šta je sve može očekivati na putu. U ovom radu, autori se osvrću na faze trgovine ljudima, fokusirajući se na kriminalitet organizovanih kriminalnih grupa i položaj žrtve. Govori se o oblicima regrutovanja žrtava, načinima transpostovanja, osnovnim geografskim rutama, kao i o načinima kontrole i eksploatacije žrtava

Expert project analyses in the process of road maintenance management

Za potrebe učinkovitog gospodarenja održavanjem cestovne mreže neophodno je raspolagati s ažurnom informacijskom osnovom i odgovarajućim modelom za odlučivanje. U radu se daje prikaz metodološkog postupka za ekspertne projektne analize za radove na održavanju i poboljšanju cesta uz korišćenje Baze Cestovnih Podataka (BCP) i primjenu HDM-4 modela. Postupak je uspješno primjenjen i prihvaćen u apliciranju zahtjeva za financiranje radova na održavanju i poboljšanju cestovne mreže od strane međunarodnih financijskih institucija (Svjetska Banka, EIB i EBRD) tijekom 2012-e godine.An updated information system, and an appropriate decision making model, must be put in place for an efficient road maintenance management. A methodological procedure for expert project-level analyses of road maintenance and improvement activities, based on the Road Data Base (RDB) and the HDM-4 model, is presented in the paper. The procedure was successfully applied and accepted in 2012, in the scope of application for funding of road network maintenance and improvement by international financing institutions (World, Bank, EIB and EBRD)

Utilizing metabolites from curcuma longa for the development of ph-responsive test strips

Introduction: Metabolites from Curcuma longa show pH-dependent color-changing properties. During this study, test strips were developed using Curcuma longa metabolites, which enable the rapid estima- tion of acidity/alkalinity in natural and artificial samples. Methods: Commercially available Curcuma longa powder (5.00 g) was mixed with ethanol (45 mL) and subjected to 30 minutes of ultrasonic extraction. After 60 minutes of settling, the resulting suspension was filtered and supplemented with ethanol to reach a final volume of 50 mL. Circular pieces of filter paper were immersed in 15 mL of the colored filtrate in Petri dishes for 10 minutes. The impregnated pieces of filter paper were then dried at 65°C for 10 minutes and cut into desired rectangular shapes. Results: Analysis of the prepared test strips’ behavior was conducted across a pH range from 0 to 14, en- compassing various solutions (HCl, NaOH, and buffered solutions) whose pH values were measured by a pH meter. The test strips exhibited a yellow-orange color at pH values below 8.5, while a brown color was observed at pH values of 8.5 and above. Conclusion: The experimental data obtained in this investigation demonstrate significant agreement with the literature value for the first pKa of curcumin (pKa1=8.4), a compound displaying the distinctive orange color found in dry Curcuma longa powder, and possessing pH-dependent color-changing char- acteristics. Therefore, test strips prepared from an ethanolic extract of Curcuma longa powder constitute a promising tool for the routine assessment of acidity/alkalinity across various samples in molecular bi- ology, (bio)chemistry, pharmacy, medicine, and related fields.The poster presentation of the abstract, including a 3-minute oral presentation, was conducted by the corresponding author on the first day of the conference in Belgrade, on October 6th 202

Two step sintering of the ZnTiO3 nanopowder

Metastabile nanopowder ZnTiO3 pressed into cylindrical compacts at 200 MPa was submitted to conventional heating with isothermal holding at 931oC for 10 minutes, 25 minutes and 40 minutes. Same compacts were heated with two-step sintering schedule with maximal 912oC and isothermal holding at 896oC, for approximately the same holding times as with isothermal. Shrinkage during heating was monitored with dilatometric device, while microstructure was determined with atomic force microscopy. XRD patterns were collected for the most prominent samples. Sintered specimens microstructure showed differences introduced during last sintering stage by two heating schedules

Managing the Hazardous Chemical Waste in Laboratories: Are We on the Right Path?

• Introduction and scope The use of hazardous chemicals during laboratory analyses, experiments, and research leads to the generation of hazardous waste [1]. Proper primary sorting of this waste can be challenging due to the necessity of preventing unwanted interactions and the formation of even more hazardous secondary substances [2]. The aim of this study is to provide insight into the management of hazardous chemical waste in Serbian laboratories. • Methodology A preliminary survey conducted in August 2023 with chemists and physical chemists (n=11) employed in different laboratories in Serbia was based on two fundamental questions: (1) How do you sort hazardous chemical waste, and (2) Do you believe it is necessary to have additional education and training on this issue? • Results The survey results are as follows: 73% of participants primarily sort liquid hazardous chemical waste into three categories: inorganic, halogenated organic, and non-halogenated organic waste. In addition, 100% of respondents consider it would be necessary to have additional education on laboratory hazardous chemical waste and its primary categorization since it is a part of their daily work. • Conclusion From presented results and after studying the existing Serbian legal regulations in the field of hazardous waste management [3] [4], a lack of clear and unambiguous protocols defining precise methods for the primary sorting of laboratory hazardous chemical waste can be observed. In the context of future studies, a more in-depth exploration of this subject is warranted, with a particular emphasis on offering recommendations for the enhancement of the legal framework within this domain [5

Synthesis of Iodine monochloride Using a Chlorine Solution in Glacial acetic acid with Simultaneous Disinfectant Generation

Iodine monochloride is an interhalogen compound that acts as an iodinating reagent for aromatic compounds, a halogenating agent for unsaturated compounds and for cleavage of carbon-metal bonds. The direct synthesis of solid iodine monochloride from elements is a very hazardous procedure in the laboratory due to the high toxicity of chlorine and iodine. In this paper, a safer method for obtaining a solution of iodine monochloride in glacial acetic acid, which is used as a reagent for determination of the iodine value of fats and oils, is presented. Laboratory preparation of iodine monochloride solution in glacial acetic acid is described in AOAC Official Method 993.20 - Iodine Value of Fats and Oils: chlorine gas passes through the iodine solution in acetic acid until a change in the colour of the solution is observed. If excess of chlorine is present in the resultant solution, it must be neutralised by adding of iodine solution in acetic acid. The main disadvantage of this method is the barely noticeable change in colour from brown to reddish brown and the lack of a procedure for the safe removal of chlorine excess after preparing the reagent. Considering the fact that chlorine gas is soluble in glacial acetic acid, we have overcome the mentioned deficiencies of AOAC Official Method 993.20 by introducing chlorine gas into the glacial acetic acid at 298K. The figure shows the process to obtain a chlorine solution in glacial acetic acid. The necessary volume of concentrated hydrochloric acid is added to the solid potassium permanganate in the reactor vessel (A) and the container is immediately closed. Chlorine gas is released, which flows through concentrated sulphuric acid (B) to remove moisture. After that, the chlorine is introduced into a vessel filled with glacial acetic acid (C). The excess chlorine is then dissolved in a 10% (w/v) sodium hydroxide solution (D) to produce a mixture of sodium hypochlorite and sodium hydroxide, which requires dilution with an appropriate volume of water to obtain an alkaline hypochlorite solution, which has strong disinfectant properties. The chlorine content in the glacial acetic acid solution is determined by iodometric titration; the same technique is used for determining the hypochlorite content after absorbing the excess chlorine in the sodium hydroxide solution. The final solution of iodine monochloride is prepared simply by adding a calculated volume of chlorine solution in glacial acetic acid to a specified volume of iodine in the same solvent. The results of our study demonstrate that the reaction of 0.12 mol potassium permanganate with 80 cm3 concentrated hydrochloric acid produce 200 cm3 of 0.85 mol/dm3 chlorine solution in glacial acetic acid and 250 cm3 of 0.34 mol/dm3 alkali sodium hypochlorite solution. This amount of chlorine solution in glacial acetic acid is sufficient to prepare approximately 3 dm3 of 0.1 mol/ dm3 iodine monochloride solution in the same solvent.This poster presentation was presented at the 22nd European Meeting on Environmental Chemistry 5-8 December 2022, Ljubljana, Slovenia [https://www.emec22.com

Theoretical and experimental study of polycrystalline phases obtained by the nanometric ZnTiO3 powder sintering

In this study we have combined two research methods: structure prediction of ZnTiO3 using computational SPuDS software, and the characterization of binary oxides obtained from ZnO TiO2 system. Pure nanosized ZnTiO3 (99.5%), was compacted in cylindrical shape specimens by uniaxial double sided compaction and then sintered in air atmosphere in a dilatometric device [1,2]. One compact was sintered up to 915 °C to retain metastabile ZnTiO3 and held 5 minutes on that temperature, and another one at the same conditions, but now up to 970 °C to induce phase transition and to obtain stabile Zn2TiO4 and TiO2 according to phase diagram [2]. Reheated samples obtained at different characteristic temperatures in air were analyzed by X-ray diffraction (XRD). The infrared attenuated total reflectivity measurements confirmed XRD results. In order to estimate theoretical stability of these perovskite structure, Goldschmidt tolerance factor Gt and global instability index GII were calculated. Furthermore, the Ti valence states were determined by bond valence calculations (BVC). Also, we have investigated the formation of new phases (Zn2Ti3O8, TiO2 and Zn2TiO4) originating from ZnTiO3 with temperature change, as well as the relation between the crystal structures which have been predicted and the structure of the phases we have experimentally observed