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Nasl. z nasl. zaslona. Opis vira z dne 21. 6. 2023. Bibliografija: str. 11-12. Abstract.

Nasl. z nasl. zaslona. Opis vira z dne 16. 5. 2023. Bibliografija: str. 16-18. Abstract.

Nasl. z nasl. zaslona. Objavljeno na spletu: 20. 3. 2023. Opis vira z dne 17. 4. 2023. Bibliografija: str. 1236–1237.

AR Chemistry edukativna je aplikacija koja korisniku omogućuje vizualizaciju i interakciju s atomima i molekulama uz pomoć proširene stvarnosti. Budući da je jedna od najpopularnijih namjena proširene stvarnosti upravo edukacija, ova tehnologija je odabrana kao osnova aplikacije zbog svoje ugrađene sposobnosti vizualizacije pri objašnjavanju koncepata koji zahtijevaju razumijevanje prostornih odnosa. Za izradu aplikacije korištena je Vuforia za AR funkcionalnosti te Unity pri samom razvoju aplikacije. Dobivena aplikacija se može instalirati i koristiti na Android pametnim mobilnim uređajima s AR sposobnostima. AR Chemistry is an educational application that allows the user to visualize and interact with atoms and molecules with the help of augmented reality. Since one of the most popular use cases for augmented reality is education, this technology was chosen as the base of the application for its embedded visualization ability while explaining concepts that require understanding of spatial relations. To develop the application, Vuforia was used for AR functionalities and Unity for developing the app in general. The built version of the app can be installed and used on Android smart devices that have AR capabilities.

Nasl. z nasl. zaslona. Opis vira z dne 9. 1. 2023. Št. članka: 120916. Bibliografija: str. 7. Abstract.

Finding a maximum clique is important in research areas such as computational chemistry, social network analysis, and bioinformatics. It is possible to compare the maximum clique size between protein graphs to determine their similarity and function. In this paper, improvements based on machine learning (ML) are added to a dynamic algorithm for finding the maximum clique in a protein graph, Maximum Clique Dynamic (MaxCliqueDyn; short: MCQD). This algorithm was published in 2007 and has been widely used in bioinformatics since then. It uses an empirically determined parameter, Tlimit, that determines the algorithm’s flow. We have extended the MCQD algorithm with an initial phase of a machine learning-based prediction of the Tlimit parameter that is best suited for each input graph. Such adaptability to graph types based on state-of-the-art machine learning is a novel approach that has not been used in most graph-theoretic algorithms. We show empirically that the resulting new algorithm MCQD-ML improves search speed on certain types of graphs, in particular molecular docking graphs used in drug design where they determine energetically favorable conformations of small molecules in a protein binding site. In such cases, the speed-up is twofold.

In this work, we developed and optimized a method for the analysis of PAHs and nitro-PAHs in atmospheric particulate matter (PM) samples by using thermal desorption gas chromatography coupled with electron ionization single quadrupole mass spectrometry (TD-GC-(EI)-MS). The method uses thermal desorption from a PM on a filter sample as means of sample introduction to a column and obviates the need for complex extraction procedures, which are time-consuming and require environmentally unfriendly solvents. Moreover, the possibility of systematic errors is minimized and a significantly smaller amount of sample is required compared to traditional techniques requiring a pre-extraction step (approx. 10-times). Thirteen PAHs and three nitro-PAHs were used during method development. Although Tenax cartridges are typically used to capture volatile pollutants from the air, we found that glass-wool liner is the most suitable trap for the examined analytes after desorption from a quartz filter. Among the various instrument parameters which were tested and optimized, TD desorption flow and hold time, and temperature of the cooled injection system (CIS) proved to be most critical. We also found out that the matrix effect is especially pronounced in the case of high PM loadings, which should be kept in mind when planning the analysis. After the optimization, standard reference materials (ERM-CZ100 and NIST 1648a) were used for partial method validation and finally, real PM10 and PM2.5 samples from two Slovenian cities were successfully analyzed.

Izvajanje pouka v šolah pogosto poteka na tradicionalen način s frontalnim poučevanjem in predavateljem v središču pozornosti, kljub temu da je za kakovostno usvajanje znanja, spretnosti in veščin bistveno zagotoviti okolje, v katerem so v središču aktivni učenci. Informacijsko-komunikacijska tehnologija omogoča preoblikovanje učnega procesa, ena od takšnih možnosti je uporaba poddaj. Raziskave kažejo, da slednje omogočajo dobro alternativo tradicionalnemu načinu učenja in poučevanja kemije, vendar ga samo z uporabo poddaj ne more v celoti nadomestiti. Pri pouku kemije predstavlja uporaba poddaj inovativen pristop, ki pa od avtorja učnih enot zahteva več priprav in poglobljeno delo, predvsem pri poučevanju slovensko govorečih učencev, saj je količina slovenskih poddaj omejena. Ker na slovenskem prostoru še ni bilo narejene raziskave s področja uporabe poddaj pri pouku kemije, je namen tega magistrskega dela ovrednotiti uporabno vrednost poddaj pri pouku kemije. Z uporabo svetovnega spleta in člankov sem pregledal področje uporabe poddaj pri pouku kemije. Z vprašalnikom sem preveril, kaj o uporabi in o ustvarjanju lastnih poddaj za učenje kemije menijo dijakinje in dijaki, z intervjuvanjem izbranih srednješolskih učiteljic pa sem spoznal, na kakšen način se poddaje morda že uporabljajo pri pouku kemije v Sloveniji ter kakšne prednosti in omejitve glede njihove uporabe prepoznavajo učitelji kemije. Ugotovil sem, da srednješolci podpirajo uporabo poddaj, zlasti video različic, za učenje kemije, a prednost dajejo tradicionalnim oblikam učenja. Za ustvarjanje lastnih poddaj ne kažejo velikega interesa, se pa učiteljicam ta aktivnost zdi zelo poučna. Pravijo, da pri svojem delu poddaj ne uporabljajo pogosto, raje se poslužujejo drugih aktivnosti. Največjo oviro vidijo v časovni stiski s sledenjem učnim ciljem po učnem načrtu. Magistrsko delo utira pot novim spoznanjem o uporabi poddaj na področju raziskovanja v kemijskem izobraževanju in predstavlja velik doprinos pedagogiki kemije. Education in schools often takes place in the traditional way, with frontal, teacher-centred instruction, even though it is essential for best acquisition of knowledge, skills and abilities to provide a student-centred environment. Information and communications technology enables transformation of the learning process. One of such possibilities is the use of podcasts. Research shows that podcasts provide a good alternative to the traditional way of learning and teaching chemistry, but it cannot be completely replaced by using podcasts alone. The use of podcasts in chemistry is an innovative approach, which requires more preparation and in-depth work from the teacher, especially in the teaching of Slovene-speaking students, as the number of Slovene podcasts is limited. As no research has yet been done in Slovenia in the field of the use of podcasts in chemistry lessons, the purpose of this master's thesis is to evaluate the usefulness of podcasts in chemistry lessons. Using the World Wide Web and research articles, I reviewed the field of application of podcasts in chemistry lessons. With the questionnaire I investigated what students think about the use and creation of their own podcasts for learning chemistry, and by interviewing selected high school teachers I found out how podcasts may already be used in chemistry lessons in Slovenia and what advantages and limitations of their applications are recognized by chemistry teachers. I have found that high school students support the use of podcasts, especially video versions, for learning chemistry, but they prefer traditional forms of learning. They do not show much interest in creating their own podcasts, but the teachers find this activity very instructive. Teachers report that they do not use podcasts often in their work. They prefer to use other activities and see the biggest obstacle in time constraints by following the learning goals according to the curriculum. The master's thesis paves the way for new insights into the use of podcasts in the field of research in chemical education and represents a major contribution to the pedagogy of chemistry.

As the global demand for propene (propylene) is increasing, classic commercial production processes are becoming unable to keep up. Non-oxidative dehydrogenation, although hitherto underutilised industrially, has been put forward as a viable and green alternative, which is already used in a few commercial processes. In this work, we present detailed first-principles calculations of this reaction over a chromium oxide catalyst, which is the cornerstone of the Catofin ® process. A complete reaction pathway for the dehydrogenation of propane to propene and ultimately to propyne (methylacetylene) was considered. Cracking, which can yield C1 and C2 hydrocarbons, and the deactivation of the catalyst because of coking were also included and modelled. We used density functional theory calculations with the Hubbard model to study the structure of the involved intermediates, their adsorption and their interconversion to explain how chromium oxide catalysts facilitate this reaction and which processes cause their deactivation. We showed that the interaction of the hydrocarbons and molecular hydrogen with the catalytic surface is rather weak, resulting in low surface coverages, but increasing with multiple bonds present in hydrocarbons. Having constructed the potential energy surface with all the intermediates and the transition states linking them, we proposed a kinetic model for the reaction. Kinetic Monte Carlo simulations were performed at experimentally relevant temperatures (700–1000 °C), pressures (up to 10 bar) and inlet mixture compositions to study the kinetics of the reaction and discover the rate determining steps. As the reaction is highly endothermic, considerable conversions only occur at high temperatures. The accumulation of propene and propyne in the reaction mixture adversely affects the reaction rate and selectivity. Higher pressures increase the reaction rate but also increase the rate of coke formation, which poisons the catalyst. Deactivation of the catalyst has a strong temperature dependence and is caused by the accumulation of C∗ and CH3CC∗ on the surface, which are hard to remove even with hydrogen.

U pozvanom predavanju obrađeni su mehanizmi nastajanja omega-3 nezasićenih masnih kiselina, njihov metabolizam u ljudskom tijelu kao i efekti koje imaju na ljudski organizam.

Kemija je prirodna znanost neophodna za razumijevanje svijeta oko nas jer pojašnjava procese, pojave i događaje u svakodnevnom životu. Sve što koristimo u svakodnevnom životu zapravo je kemijski preparat, a osim što su poučni, kemijski pokusi mogu biti i zabavni i lijepi. Cilj radionice je zanimljivim pokusima pojednostavniti glavne kemijske pojmove i približiti ih učenicima viših razreda osnovne škole. U sklopu radionice izvoditi će se eksperimenti za koje su potrebni jednostavni i bezopasni sastojci.

Radionica je namijenjena starijim učenicima koji se ne susreću prvi put s kemijskim pojmovima i procesima. Cilj radionice je pomalo suhoparno i zamorno gradivo učiniti zanimljivijim te ukazati na korelacije sa svakodnevnom životom. Ukoliko se za neku informaciju i gradivo pronađe korelacija sa (svakodnevnim) životom, tada se gradivo lakše uči i duže pamti. Stoga će se u sklopu radionice izvesti pokusi koji uključuju predmete iz svakodnevnog života.

Tailings of old mines often contain metals, which were not of economic interest or could not be recovered with the existing technology at the time of active mining. This is especially true for metals that often occur as by-products in Cu-Pb-Zn-(Ag-Au) ores as Sb, Mo, Ge, and In. A fundamental characterization of some tailings is presented in terms of their mineralogy and content of valuable metals which could be extracted to finance a possible remediation and improve the supply of the EU with critical metals. Tailings from active and abandoned mines in Serbia (Bor, porphyry Cu/Au; Krivelj, porphyry Cu/Au; Blagodat, hydrothermal Pb-Zn; Lece, epithermal Au; Rudnik, hydrothermal/skarn Pb-Zn) and North Macedonia (Sasa, Pb-Zn; Probištip, Pb-Zn; Bučim, porphyry Cu; Lojane, fault-bound vein-type low-temperature As, Sb, Cr at the contact of rhyolite and serpentinite) were studied. Analysis for major and trace elements used a multi-method approach (lithium borate fusion and ICP-MS/OES analysis, gravimetric analysis, instrumental neutron activation analysis, total digestion ICP-OES, infrared spectroscopy) with mineral identification by scanning electron microscopy. Concentrations of the major commodity elements (Cu, Pb, Zn, Au, Ag) varies within several orders of magnitude depending on mineralogy and ore type. Critical metals (Co, Ga, Ge, Sb) contents are low with some exceptions. Some tailings contain moderate to elevated potentially toxic element levels (As, Cd, Pb, Tl). For the sample from Probištip which yielded the highest valuable metal concentrations (>5000 ppm Pb, 4020 ppm Zn), a heavy mineral concentrate of the sand size fraction (0.06 mm to 0.5 mm) was produced and analyzed by SEM and LA-ICP-MS for additional rare phases and trace elements. In all tailings studied, additional milling would be needed to separate ore from gangue minerals. Increasing metal prices might facilitate feasibility studies for some of the localities in the future, despite the limited quantitative information about the characterized tailings.

U svrhu promocije znanosti i istraživanja od najranije dobi, buđenja interesa za znanstveno- istraživački rad te obrazovanje koje se provodi u sklopu programa “Škola za život”, provele su se interaktivne radionice pod nazivom Čarolija pokusa i Čarobni svijet mikroorganizama. Cilj radionice je popularizirati znanost od najranije dobi te potaknuti učenike na interes za prirodne znanosti s naglaskom na kemiju. Kroz znanstvene eksperimente, učenike se potiče na samostalno opažanje i kritičko razmišljanje te primjenjivost i važnost prirodnih znanosti u svakodnevnom životu. Radionice su se održale u OŠ SAVSKI GAJ, Zagreb.

Cilj radionice je zanimljivim pokusima pojednostavniti temeljne kemijske pojmove i približiti ih učenicima nižih razreda osnovne škole koji se s njima sada prvi put susreću. U tu svrhu izvoditi će se jednostavni, vizualno dojmljivi pokusi koji lako, jasno i nedvosmisleno pojašnjavaju osnovne kemijske pojmove, pojave i procese. Pokusi koji se izvode su jednostavni, a njihova glavna karakteristika je upotreba predmeta iz svakodnevnog života.

Summary Mutations causing amyotrophic lateral sclerosis (ALS) often affect the condensation properties of RNA-binding proteins (RBPs). However, the role of RBP condensation in the specificity and function of protein-RNA complexes remains unclear. We created a series of TDP-43 C-terminal domain (CTD) variants that exhibited a gradient of low to high condensation propensity, as observed in vitro and by nuclear mobility and foci formation. Notably, a capacity for condensation was required for efficient TDP-43 assembly on subsets of RNA-binding regions, which contain unusually long clusters of motifs of characteristic types and density. These “binding-region condensates” are promoted by homomeric CTD-driven interactions and required for efficient regulation of a subset of bound transcripts, including autoregulation of TDP-43 mRNA. We establish that RBP condensation can occur in a binding-region-specific manner to selectively modulate transcriptome-wide RNA regulation, which has implications for remodeling RNA networks in the context of signaling, disease, and evolution., Graphical abstract, Highlights • TDP-43 mutants affect condensation properties to a similar extent at multiple scales • Binding-region condensates form on long RNA regions with dispersed UG-rich motifs • RBPchimera-CLIP indicates homomeric interactions promote molecular-scale condensates • Condensation selectively tunes the regulatory capacity of TDP-43; e.g., autoregulation, The condensation propensity of an RNA-binding protein tunes its binding to specific RNA regions across the transcriptome and affects its RNA processing functions. Formation of these “binding-region condensates,” promoted by specific motif types that are dispersed across long RNA regions, expands the ways in which RNA binding can be selectively controlled beyond canonical RNA-binding domains.

Experimental work is an important component of science subjects at all educational levels. The implication of green chemistry ideas indicated the need for optimization of traditional experimental work by implementing green chemistry principles to promote sustainable development. The aim of the study is to present findings from a systematic literature review on the use of experimental work in science education from green chemistry perspectives in the literature from 1995 to 2020. Thus, three electronic databases were reviewed following the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. The literature search identified a total of 1199 papers from Web of Science (N = 419), Scopus (N = 578), and Education Resources Information Center (ERIC) (N = 202). After applying inclusion/exclusion criteria, 263 papers were obtained and then analyzed in further detail. The findings highlighted trends in the integration of green chemistry principles into experimental work from primary to tertiary education levels and identified a literature gap, as well as the challenges and the possibilities for future development. The review outlined various opportunities for active learning within experimental work from green chemistry perspectives using a range of methods, with a particular focus on practical, hands-on, and laboratory activities.

"Available online 11 June 2022", The objective of this study was to assess the degradation rates of chrysene and benzo[a]pyrene, as well as the removal of aluminium and iron from contaminated soil collected in the upper layer (030 cm) in Lagos, Southwest Nigeria. Trametes versicolor was isolated from this soil and used in degradation experiments, with plantain peels as support. After 8 weeks, 82.0% of chrysene degradation was achieved by T. versicolor, and by adding support this increased to 91.0%. Benzo[a]pyrene was less degradable, with 38.0% and 49.1% of degradation, respectively. Trametes versicolor was also capable of accumulate 46.1% of aluminium and 57.2% of iron. By adding plantain peels, these amounts increased to 48.2% and 61.8%, respectively. At the same time, laccase was produced by Trametes versicolor on plantain peels, achieving 37.8 U/g of crude laccase during SSF at 30 °C for 3 weeks. Laccase degradation experiments were set up in packed-bed reactor (PBR), with a constant feed of 21.6 mL/day of laccase, with and without mediators. In 35 days, 75.9% degradation of chrysene was achieved by laccase. The highest degradation was observed with ABTS (2,2-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt) as mediator, 87.9%. Benzo[a]pyrene degradation with laccase reached 35.6%, raising to 38.8 % with ferulic acid as mediator. In addition, 99.2% of iron and 99.6% of aluminium was removed by laccase, being the treatment for this last mediated with ABTS., This study was supported by the Portuguese Foundation for Science and Technology (FCT), Portugal under the scope of the research project PTDC/AAG-TEC/5269/2014, the strategic funding of UID/BIO/04469/2013 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ziva Vipotnik is a recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) - Doctoral Program in Applied and Environmental Microbiology (DP_AEM); operation NORTE-08-5369-FSE-000060; co-financed by North 2020 through the European Social Fund (ESF)., info:eu-repo/semantics/publishedVersion

The Eighth Central European Conference “Chemistry towards Biology” was held in Brno, Czech Republic, on 28 August–1 September 2016 to bring together experts in biology, chemistry and design of bioactive compounds promote the exchange of scientific results, methods and ideas and encourage cooperation between researchers from all over the world. The topics of the conference covered “Chemistry towards Biology”, meaning that the event welcomed chemists working on biology-related problems, biologists using chemical methods, and students and other researchers of the respective areas that fall within the common scope of chemistry and biology. The authors of this manuscript are plenary speakers and other participants of the symposium and members of their research teams. The following summary highlights the major points/topics of the meeting.

The methane activation and methane dry reforming reactions were studied and compared over 4 wt % Ni/CeO2 and 4 wt % Ni/CeZrO2 (containing 20 wt % Zr) catalysts. Upon the incorporation of Zr into th...

The production of biobased copolymers such as poly(styrene-co-butyl acrylate-co-methacrylic acid) for paints and coating applications is indispensable for the establishment of sustainable biorefine...

IR spectroscopy can be a non-destructive and straightforward probing tool in the battery research. However, its application has been limited due to the difficulties related to the handling and interpretation of ex situ samples along with the lack of widely applicable in situ and operando cells. Herein, we show a simple, operando ATR-IR two electrode pouch cell with an IR-transmissive silicon window and discuss its advantages and limitations. This setup is applied to the study of the polyanthraquinone (PAQ) reaction mechanism in Li- and Mg-organic batteries. During the reduction/oxidation process of the PAQ, not only the conversion of both C O groups into C–O– species is observed, but also the formation of an intermediate semiquinone radical anion as an intermediate product. Furthermore, continuous measurement of IR spectra allows visualization of the gradual solid-electrolyte interphase (SEI) buildup on the cathode during cycling.

U ovome radu objašnjene su osnove tehnologije proširene stvarnosti te glavni koncepti u procesu njezine izvedbe. Opisana je primjena proširene stvarnosti na području obrazovanja, a poseban naglasak stavljen je na proširenoj stvarnosti u aplikacijama i igrama vezanim uz kemiju. Izrađen je prototip obrazovne aplikacije koja sadrži elemente proširene stvarnosti s fokusom na kemijske spojeve. Aplikacija je implementirana u Unity razvojnom okruženju uz korištenje Vuforia programskog alata. Cilj ove aplikacije je brže i bolje usvajanje znanja o kemijskim spojevima uz pomoć interaktivnih elemenata proširene stvarnosti. Korisnik uči tako da pronalazi objekte iz vlastite okoline na temelju kojih bi se prikazao kemijski spoj koji je glavni gradivni element tog objekta i neke zanimljivosti vezane uz taj spoj. This paper explains the basics of augmented reality technology and the fundamental concepts in the process of its implementation. The use of augmented reality in the field of education is described, and special emphasis is placed on augmented reality applications and games based on chemistry. A prototype of an educational application containing augmented reality elements with a focus on chemical compounds was developed. The application is implemented in a Unity development platform using the Vuforia software tool. The primary purpose of this application is the faster and better acquisition of knowledge about chemical compounds with the help of the augmented reality interactive elements. The user learns by finding specific objects from his environment. When the object is detected, the main chemical compound of that object and some interesting facts related to that compound are shown on the screen.

Globalna pandemija virusa SARS-CoV-2 postavlja izazove pred sve aspekte života pa tako i poslovni. U cijelom svijetu obrazovanje se preselilo u virtualno okruženje te su nastavnici morali u izrazito kratkom periodu modificirati nastavni proces i odlučiti u kojem je smjeru najbolje krenuti kako bi kvaliteta nastave ostala na što višoj razini. Iako se za predavanja i seminare održavanje u online okruženju pokazalo kao najbolji odabir obzirom na epidemiološke mjere, pojedine oblike nastave nije moguće odraditi na taj način. Laboratorijsku nastavu čijim se provođenjem stječu mnoge vještine, trebalo je prilagoditi novim okolnostima. Vježbovna nastava kolegija Kemija i Biokemija održana je s manjim brojem studenata u grupi. Kako bi se spriječio fizički kontakt između pojedinih vježbovnih grupa, svaka je grupa imala vježbe u točno određenom danu u tjednu. Studenti su bili dužni prije dolaska u prostor Zdravstvenog veleučilišta izmjeriti temperaturu te tijekom nastave koristiti zaštitne maske. Prostor laboratorija je redovito dezinficiran. Radi što boljeg prozračivanja, tijekom izvođenja vježbi prozori laboratorija bili su širom otvoreni. Studenti su vježbovnu nastavu odradili tako da je iz pojedine vježbe odabran najznačajniji dio, proveden je manji broj ponavljanja i ispravljanja pojedinih zadataka. Određene zadatke studenti su radili u grupi, ali su u najvećoj mogućoj mjeri poticani na samostalan rad. Od studenata se očekivalo da unaprijed prouče fotografije, pisane i video materijale koji su im bili dostupni putem platforme Moodle i da riješe kemijske zadatke. Nastavu je svaki dan održavao jedan nastavnik te je na taj način onemogućen njihov međusobni kontakt u svrhu primjene protuepidemijskih mjera. Možemo biti zadovoljni ishodom jer tijekom održavanja nastave nije bilo niti jednog slučaja zaraze među nastavnicima i studentima. Nastavom u laboratoriju studenti su stekli vještine koje ne mogu usvojiti u virtualnom okruženju.

U radu je prikazana primjena analize rezultata provedenog eTwining projekta[1] u nastavi kemije i biologije. Tijekom 2019. uključili smo se s učenicima koji pohađaju dodatnu nastavu kemije i biologije u međunarodni eTwining project “Interesting science for kids”, a realiziran je do kraja školske godine 2020./2021. Učenici su tijekom izvođenja dodatne nastave kemije izvodili pokuse na temu Staničnog disanja i svoje rezultate prikazali ostalim sudionicima projekta. Izdvojeni pokusi izvedeni su tijekom redovne nastave kemije pri obradi tema Što je kemija?, Svojstva i vrste tvari, Smjese tvari, Tvari u prirodi, te nastavi biologije pri obradi tema Osnovna obilježja živih bića i organiziranost u prirodi, Prijenos tvari kroz organizam, Disanje živih bića. Pokusi su provedeni u tri od šest razredna odjela sedmog razreda. naše škole. Pomoću digitalnih alata[2] ispitana je usvojenost ishoda poučavanja u svih šest razrednih odjela. Uočili smo kako učenici radom na projektima razvijaju kompetencije komunikacije na materinskom jeziku, komunikacije na stranim jezicima, matematičke kompetencije i osnovne kompetencije u znanosti i tehnologiji, digitalne kompetencije, uče kako učiti, društvene građanske kompetencije, smisao za inicijativu i poduzetništvo.[3] Rezultati projekta pokazali su i kako su učenici radom na eTwinning projeku usvojili specifične vještine korištenja znanja i metoda (vještine izvođenja eksperimenata, bilježenja rezultata i opažanja i donošenja zaključaka) koje im pomažu u objašnjavanju prirodnih zakonitosti.

Cilj radionice je zanimljivim pokusima pojednostavniti opće kemijske pojmove i približiti ih učenicima nižih razreda osnovne škole. Neki od pokusa su Šarena epruveta, Munje u epruveti, Natrij koji pleše, Zima u čaši, Plava boca i drugi.

Kemija z biokemijo je učbenik za študente visokošolskega strokovnega študija kmetijstva. V učbeniku so tudi laboratorijske vaje.

The enzyme-catalyzed degradation of the biogenic amine serotonin is an essential regulatory mechanism of its level in the human organism. In particular, monoamine oxidase A (MAO A) is an important flavoenzyme involved in the metabolism of monoamine neurotransmitters. Despite extensive research efforts, neither the catalytic nor the inhibition mechanisms of MAO enzymes are currently fully understood. In this article, we present the quantum mechanics/molecular mechanics simulation of the rate-limiting step for the serotonin decomposition, which consists of hydride transfer from the serotonin methylene group to the N5 atom of the flavin moiety. Free-energy profiles of the reaction were computed by the empirical valence bond method. Apart from the enzymatic environment, the reference reaction in the gas phase was also simulated, facilitating the estimation of the catalytic effect of the enzyme. The calculated barrier for the enzyme-catalyzed reaction of 14.82 +/- 0.81 kcal mol(-1) is in good agreement with the experimental value of 16.0 kcal mol(-1), which provides strong evidence for the validity of the proposed hydride-transfer mechanism. Together with additional experimental and computational work, the results presented herein contribute to a deeper understanding of the catalytic mechanism of MAO A and flavoenzymes in general, and in the long run, they should pave the way toward applications in neuropsychiatry.

Organocatalyzed ring-opening polymerization (ROP) of e-caprolactone (CL) and 4,4′-bioxepanyl-7,7′-dione as a bis-lactone cross-linker was performed within the oil-in-oil high internal phase emulsions (HIPEs) at 50 °C. In this way, the cross-linked poly(e-caprolactone) (PCL) polyHIPE foams of ∼85% porosity were synthesized. Thermomechanical properties of the prepared polyHIPEs were studied and proved to greatly depend on a degree of PCL cross-linking. The melting and crystallization temperatures as well as the degree of crystallinity of PCL polyHIPE foams decrease with an increasing cross-linking degree. Semi-crystalline polyHIPEs demonstrate shape memory behavior with excellent shape fixity and shape recovery. At an appropriate degree of PCL cross-linking, the polyHIPE temporary shape can be fixed at room temperature, while a transition to the permanent shape occurs upon heating at 40 °C. Moreover, a two-way shape memory behavior of the PCL polyHIPEs under constant stress was observed.

Despite the fact that the methanol synthesis process includes industrially some of the most important catalytic chemical reactions, it is still not clear how different gaseous species impact cataly...

While the function of enzymes has been well-known to researchers for decades, the driving force behind it is still a hotly debated topic. Herein, we report significant evidence for electrostatics being that driving force, using a simple, computationally inexpensive, multiscale model of monoamine oxidase A and phenylethylamine. We found that electrostatics provided by the enzyme substantially enhances the reaction by all the considered criteria (lowering the energy barrier, increasing charge transfer, decreasing the highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gap, increasing the dipole moment). The catalytic effect can be rationalized by the stabilizing interaction between the dipole moment of the reacting moiety and the electric field exerted by the charged environment. Both the dipole moment and the electric field are perceivably larger in the transition state as compared to the state of reactants; hence the transition state is stabilized to a larger extent and bett...

V diplomskem delu sem obravnaval delo Kmetijska kemija, avtorja Matije Vertovca, ki velja za prvi kemijski priročnik v slovenskem jeziku. V uvodu sem predstavil Vertovčevo življenje in delo, opisal pa sem tudi nezanemarljiv pomen, ki ga je imel in ima Vertovec in njegovo delo za slovenski jezik in narod. Poglavitni cilj in namen diplomske naloge je bila analiza kemijskih terminov, ki jih je Vertovec zapisal v svojem delu Kmetijska kemija. Iz prvega poglavja Vertovčevega dela sem izpisal vse termine, za katere menim, da sodijo na področje kemijske terminologije, jim v Kemijskem slovarju poiskal ustrezne definicije ter s pomočjo Slovenskega etimološkega slovarja preverjal njihov izvor. Ugotavljal sem torej, koliko terminov je prevzel iz nemškega, grškega, latinskega jezika, koliko je vzel izrazov, ki so bili v slovenskem jeziku že zakoreninjeni in uveljavljeni in koliko je takih, ki jih je najverjetneje poslovenil kar sam. Ugotovil sem, da je večina izrazov izvor v slovanski jezikovni veji, torej so bili že zakoreninjeni v slovenskem jeziku. In my degree I did a research on the literary work called Agricultural chemistry (Kmetijska kemija) by Matija Vertovec, this is the first chemistry manual written in Slovene language. In the introduction part of my work I presented the life and work of the author Matija Vertovec and then deepened my research with the importance of the author and his work for the Slovene language and the Slovene nation. After that, I moved to the main aim of my degree, which was to analyse the etymology of terms used in the manual. Firstly, I collected and analysed all the terms written in the first chapter of the manual, for which I thought belong to the field of chemical terminology. Then I found their definitions with the help of The Chemical dictionary (Kemijski slovar) and furthermore used The Etymology dictionary (Etimološki slovar) to research upon their origin. I was trying to explore how many terms were taken over from the German, Greek and Latin language. I also investigated the terms that were already known and established in the Slovene language and used in the manual. Lastly, I searched for those terms that the author has translated into Slovene himself. My research showed that most of the terms had their origins in the Slavic language branch and were therefore already known and established in the Slovene language.

V sodobni organski kemiji znanstveniki razpoznavajo organske spojine iz različnih naborov spektrov, kjer vsak posamezni spekter vsebuje podatke o teh spojinah, kot so vsebovani element, struktura, itd. Kemiki so veliko spojin že posneli in razpoznali, računalničarji pa izdelali programe, ki s pomočjo iskanja po podatkovnih bazah najdejo preiskovano spojino. Kljub temu kemiki vedno znova odkrivajo oz. srečujejo nove, do sedaj še neznane spojine, ki jih je potrebno ročno prepoznati oz. razvozlati, za kar lahko potrebujejo dlje časa, lahko tudi več ur ali v primeru zelo kompleksnih molekul, več dni. V okviru diplomske naloge je bil razvit algoritem, ki organske spojine analitično razpoznava, brez vnaprej znane podatkovne baze. Z uporabo IR, NMR in MS spektrov je bilo mogoče dobiti zadovoljive rezultate pri reševanju organskih molekul. Algoritem, ki je nastal v okviru diplomskega dela, je javno dostopen v obliki spletnega aplikacijskega vmesnika (ang. application programming interface - API), za katerega je bil izdelan tudi uporabniški vmesnik za enostavnejšo uporabo. In modern chemistry scientists elucidate organic compounds from different sets of spectrums in which every spectrum contains it's own information about the compound i.e.: known fragments, structure, etc. Since chemists have solved and documented a lot of these compounds computer scientists quickly created softwares which, with the help of an external databases, find the researched compound. Regardless chemists still discover new yet unrecorded compounds that they need to elucidate by hand which can take them multiple hours or, in case of highly complex molecules, even days. With this purpose an algorithm, described in this document, was developed which analitically solves organic compounds without the use of any external database. By using IR, NMR and MS spectrums the algorithm was able to get accurate results while elucidating organic compounds. The developed algorithm is available to the public in the form of a web application interface together with a user interface for simple usage.

Semi-interpenetrating polymer networks (semi-IPNs) were prepared by in situ simultaneous orthogonal polymerizations, where the linear poly(e-caprolactone) (PCL) was synthesized by ring-opening polymerization of e-caprolactone and the poly(styrene-co-divinylbenzene) (PS) network was formed by free-radical polymerization of styrene/divinylbenzene. Semi-IPNs were used as the precursors for the preparation of porous PS monoliths. To this end, the PCL domains were selectively removed by hydrolysis under basic conditions. By changing the amount of organocatalyst used for the ring-opening polymerization of e-caprolactone, the relative polymerization kinetics of both monomers was varied, which has a pronounced effect on the morphology of thus-obtained PS frameworks.

Methane is the central component of natural gas, which is globally one of the most abundant feedstocks. Due to its strong C–H bond, methane activation is difficult, and its conversion into value-added chemicals and fuels has therefore been the pot of gold in the industry and academia for many years. Industrially, halogenation of methane is one of the most promising methane conversion routes, which is why this paper presents a comprehensive review of the literature on methane activation by halogenation. Homogeneous gas phase reactions and their pertinent reaction mechanisms and kinetics are presented as well as microkinetic models for methane reaction with chlorine, bromine, and iodine. The catalysts for non-oxidative and oxidative catalytic halogenation were reviewed for their activity and selectivity as well as their catalytic action. The highly reactive products of methane halogenation reactions are often converted to other chemicals in the same process, and these multi-step processes were reviewed in a separate section. Recent advances in the available computational power have made the use of the ab initio calculations (such as density functional theory) routine, allowing for in silico calculations of energy profiles, which include all stable intermediates and the transition states linking them. The available literature on this subject is presented. Lastly, green processes and the production of fuels as well as some unconventional methods for methane activation using ultrasound, plasma, superacids, and light are also reviewed.

A new species’ class of Cu-, Ga- and Zn-based rate catalysts was prepared by a systematic co-precipitation technique at the different related pH values (6.5–8.0) along with calcination functional conditions, influencing components’ physical properties, these were characterized, and their application performance for water–gas shift (WGS) reaction was researched. Substances were analysed by various experimental methods, namely chemisorption, temperature-programmed reduction (TPR) characterisation, diffraction, physisorption and microscopy. A homogenous size dispersion of the compounds with smaller granular particles was obtained for catalysis, implemented with high pH-resulting outputs. H2 TPR profiles revealed a tailored stronger effect of Cu–Zn on Ga for process, operated with low pH-conditioned forms. Over Cu/ZnGaOX, WGS was sensitive to Cu, which was primarily active. Catalytic chemical reactivity, activity and selectivity were also found to be critically dependent on material lattice structure, copper surface area and metal–support interaction phenomena. The temperature-programmed surface reaction with mass spectrometry (TPSR–MS) measurements showed that formulations, synthesised at the pH of 8.0, enabled reaching >99% of the equilibrium yield CO conversion at 260 °C. An increase in the converted CO, oxidation and H2 productivity with the integral steam content in gaseous feed flow was achieved. The heterogeneous phase processing at the correlated pH of 7.6 demonstrated the highest formed CO product at the temperature of 200 °C, compared with literature. This is particularly promising for reagent purity hydrogen-fed fuel cells. The kinetics for each co-precipitated solid was evaluated regarding the efficiency for the WGS in a fixed bed reactor. Keywords: Syngas, Hydrogen, Cu/ZnGaOX catalyst, Water–gas shift (WGS), Steam reforming reactions, Fuel cell systems