Microstructure development and electrical properties of NiO doped alpha-Fe2O3

Poster presented at the 4th Serbian Congress for Microscopy, Belgrade, Serbia, 2010, October 11-12, 201

Energetski efikasno napajanje autonomnih potrošača korišćenjem hibridnog (fotonaponskog i dizelagregatskog) izvora

The energy efficient solution of autonomous power supply of consumers during the year, by using of a hybrid (photovoltaic and diesel aggregates) sources in the monastery Chilandar is presented in this paper. In details optimal load of diesel aggregate is discussed with a minimum consumption of fossil fuels. The results of the one year exploitation of the electricity generated from photovoltaic panels in our conditions are presented as well. Taking into consideration the specific location and importance of the monastery, the current and future needs of the monastery and particular way of life of the monks, the new hybrid system for the daily consumption of 400 kWh of energy and peak load of 80 kW has been designed and explained. It is based on the combined use of the three diesel power generators 2 x 40 kW and 80 kW, photovoltaic rated power 75 kW and battery pack for energy storage of 400 kWh. The primary objective of the new system is to reduce the consumption of diesel fuel and operating costs for the system power consumption.U ovom radu je opisano energetski efikasno rešenje autonomnog napajanja potrošača tokom godine, korišćenjem hibridnog (solarne i dizel agregata) izvora u manastiru Hilandaru. Detaljnije je razmotreno optimalno opterećenje dizel agregata sa minimalnom potrošnjom fosilnih goriva. Prikazani su rezultati jednogodišnjeg ispitivanja, u našim uslovima, dobijanja električne energije iz fotonaponskih panela. Imajući u vidu specifičnu lokaciju i značaj manastira, sadašnje i buduće potrebe manastira i specifičan način života monaha, nov hibridni sistem za dnevnu potrošnju od 400 kWh električne energije i vršno opterećenje od 80 kW je projektovan i objašnjen. Zasniva na kombinovanom korišćenju tri dizel generatora snage 2 x 40 kW i 80 kW, fotonaponskih nominalne snage 75 kW i baterije za skladištenje energije od 400 kW. Primarni cilj novog sistema je da smanji potrošnju dizel goriva i operativnih troškova za potrošnju energije sistema

International experiences in cooperative audit and lessons for Serbia

Basic characteristics of cooperative audit, its role in preservation of cooperative nature and promotion of cooperatives are analyzed in the paper. The aim of this paper is to propose measures to improve cooperative audit in Serbia based on the review of good practice in European countries. The development stages of cooperative audit, from the creation of first cooperatives in Europe until today, have been examined using the historical method, with particular emphasis on the legislative framework that regulated this field. The comparative method was used to determine the differences between individual solutions, emphasizing their advantages and disadvantages, as well as the potential impact on the development of cooperatives. The research suggests that there are different solutions, from the absence of cooperative audit, to its inclusion in the cooperative life cycle, starting from its establishment. Although legislative framework in Serbia foresee cooperative audit, this process needs to be significantly improved

Transcription Factor Activation during Signal-induced Apoptosis of Immature CD4+CD8+ Thymocytes: A Protective Role of c-Fos

Many signals that cause apoptotic cell death operate by inducing transcription and translation of other (presumably death effector) mediators, and it is well established that stimulus-induced apoptosis can often be blocked by inhibiting transcription and translation. Transcriptional regulation of apoptosis, however, is incompletely understood. To gain insight into nuclear events associated with signal-induced apoptosis during T cell development, we studied signal-induced apoptosis of ex vivo isolated immature CD8+4+ double-positive (DP) thymocytes. Stimuli utilizing the T cell receptor (TCR) signaling pathway or its parts (an αCD3/TCR monoclonal antibody, a Ca2+ ionophore, or a protein kinase C-activating phorbol ester) or a stimulus that antagonizes TCR signaling and apoptosis in T cell hybridoma (forskolin, a cyclic AMP-signaling activator) resulted in massive apoptosis of DP thymocytes. At the same time, these stimuli induced qualitatively similar but quantitatively unique patterns of inducible transcription factors (TFs) NF-κB/RelA-p50, AP-1 (Fos-Jun), and NUR-77. We focused our attention on the role of AP-1 (Fos-Jun) complex, which was strongly induced by all of the above stimuli and thus was a candidate for a proapoptotic TF. However, we found that AP-1/c-Fos induction was vital in prolonging DP thymocyte life, as judged by increased spontaneous and induced death of DP cells in Fos−/− mice. In direct support of this hypothesis, experiments with antisense oligonucleotides demonstrated that c-Fos plays an essential role in protecting normal DP thymocytes from Ca2+- and cAMP-induced apoptosis but not from TCR-mediated death. Together, these results demonstrate a physiological role for c-Fos in maintaining longevity of DP thymocytes

Possibility of Hybrid Supply of Autonomous Military Units With Electric Power

This paper presents one possible solution of hybrid electrical power supply for military units without electric connection to electric distribution network. The hybrid photovoltaic and diesel aggregates island's power supply with maximal power of 80 kW and daily energy of 400 kWh is shown in this paper. The advantages of this system are: reduced consumption of fossil fuels, efficient use of fossil fuels, reduced emissions, improved energy system reliability, ensuring continuous electric supply and increasing life of diesel engines. The working concept is such that hybrid system uses photovoltaic panels for prime power and diesel generators as a secondary source of energy. We expect creating such a system as a test installation, soon

The role of social media in the process of informing the public about disaster risks

Social media informs the public about the most important events and conveys important information. Before, during, and after disasters, social media are used to disseminate information about disasters and collect data relevant to the implementation of preparedness, response, and recovery activities and measures. Social networks are effective in disseminating information and warnings, as well as in educating the public. The subject of the research is examining the influence of demographic factors on the effectiveness of social media in informing the public about the risks of disasters. Using an online survey questionnaire and according to the snowball principle, a survey of 247 respondents was conducted in 2022. The research results show no statistically significant relationship between the respondents’ education level and the assessment of the effectiveness of social media reporting on disasters. Using social media can improve communication between stakeholders in disaster management and facilitate coordination of efforts, fostering communication and allocation of resources. To effectively use social media in disaster management, decision-makers in the disaster management system must be aware of new technologies, their disadvantages and advantages, and ways to collect and analyze data from social networks

Copolumers obtained by grafting of vinyl monomers on starch - influence of amines on synthesis and degradation processes in environment

U prvom delu ove doktorske disertacije sintetisani su kalemljeni kopolimeri polistirena i skroba emulzionom polimerizacijom u vodi uz korišćenje natrijum-laurilsulfata kao emulgatora. Ispitivan je uticaj različitih amina kao aktivatora polimerizacije na stepen kalemljenja polistirena na skrob, a ispitivanje ovog uticaj do sada nije zabeleţeno u literaturi. Promenom reakcione temperature, koncentracije monomera i inicijatora, pH vrednosti, vremena i količine aktivatora teţilo se dobijanju maksimalnih vrednosti stepena kalemljenja, a maksimalna dobijena vrednost iznosila je 32,55 %, što je za oko 8,5 % veće od najviše literaturne vrednosti. U drugom delu ovog rada sintetisani su kalemljeni kopolimeri poli(metakrilne kiseline) i skroba u vodi kao rastvaraču uz korišćenje različitih amina kao aktivatora polimerizacije (ovaj uticaj do sada nije ispitan u literaturi), sa ciljem dobijanja što većeg stepena kalemljenja. Da bi se dobile maksimalne vrednosti za stepen kalemljenja, praćen je uticaj promene reakcione temperature, reakcionog vremena, koncentracije monomera, količine inicijatora, količine aktivatora i pH vrednosti. Dobijene vrednosti za stepen kalemljenja kod kalemljenih kopolimera skroba i poli(metakrilne kiseline) su najveće do sada publikovane u literaturi. Maksimalna vrednost stepena kalemljenja iznosila je 40,92 %, što je za oko 10 % veće od najviše literaturne vrednosti. Dobijeni kopolimeri ispitivani su infracrvenom spektroskopijom sa Furijevom transformacijom i skenirajućom elektronskom mikroskopijom. U trećem delu doktorske teze praćeni su procesi degradacije dobijenih kopolimera u ţivotnoj sredini. Degradacija kopolimera u zemljištu, tj. u tri različita tipa zemljišta, trajala je 6 meseci, a za ovu namenu korišćeni su sledeći tipovi zemljišta: zemljište bogato humusom, zemljište za uzgajanje kaktusa i zemljište za uzgajanje orhideja. TakoĎe, ispitivana je degradcija kalemljenih kopolimera u veštačkoj otpadnoj vodi, dobijenoj iz reke Save. Prilikom degradacije u vodi korišćen je kontinualni protočni sistem. Gubitak mase kopolimera tokom procesa degradacije korišćen je kod obe metode za odreĎivanje vrednosti stepena degradacije. Degradacija kalemljenih kopolimera skroba i poli(metakrilne kiseline) u zemljištu i degradacija obe vrste kopolimera u veštačkoj otpadnoj vodi do sada nije zabeleţena u literaturi. Ispitivanjem je utvrĎeno da je degradacija svih uzoraka kopolimera znatno brţa u veštačkoj otpadnoj vodi, gde ceo proces degradacije traje manje od mesec dana, nego u zemljištu. Rezultati degradacije u zemljištu pokazuju da je degradacija najbrţa u zemljištu za uzgajanje kaktusa (kod kalemljenih kopolimera polistirena i skroba), a kod kalemljenih kopolimera skroba i poli(metakrilne kiseline) u zemljištu za uzgajanje orhideja. Statističkom obradom podataka, utvrĎeno je postojanje značajne korelacije izmeĎu stepena degradacije i stepena kalemljenja kod kalemljenih kopolimera skroba i polistirena, kao i udeo skroba u kopolimerima koji je neophodan da bi došlo do biodegradacije, kao i udeo polistirena u kopolimerima koji bi doveo do sprečavanja biodegradacije.In the first part of this doctoral dissertation graft copolymers of polystyrene and starch were synthesized by emulsion polymerization in water with sodium dodecyl sulfate as an emulsifier. Influence of different amines, as activators of polymerization, on the percentage of grafting of polystyrene on starch was investigated and investigation of this influence has not been noted in the literature. Changes in reaction temperature, concentration of the monomer and initiator, pH value, time and amount of activator strive to obtain maximum value of percentage of grafting and maximal obtained value was 32.55 % which was about 8.5 % higher than maximal literature value. In the second part of this study, graft copolymers of poly(methacrylic acid) and starch were synthesized in aqueous media using different amines as activator of polymerization (there is no literature data about this influence) with the aim to obtaining a higher percentage of grafting. Influence of temperature, reaction time, monomer concentration, amount of initiator, amount of activator and pH value were monitored to obtain maximum values for percentage of grafting. Obtained values for percentage of grafting of starch and poly(methacrylic acid) grafted copolymers were the highest ever obtained in literature. The maximum value for percentage of grafting was 40.92 % which was about 10 % higher than maximal literatue value. The obtained copolymers were characterized by Fourier transformed infrared spectroscopy and by scanning electron microscopy. At the third part of this doctoral dissertation, the degradation processes of copolymers were monitored in environment. Degradation of copolymers in soil, i.e. in three different type of soil, lasted for six months and for this study the following soil types were used: soil rich in humus, soil for cactus growing and soil for orchid growing. Also, degradation of graft copolymers in artificial wastewater obtaines from River Sava was monitored. During degradation in water, the continuous flow system was used. Mass loss of copolymers during degradation was used in both methods for obtaining values for measuring the degree of degradation. Degradation of poly(methacrylic acid) and starch grafted copolymers in soils and degradation of both types of copolymers in the artificial waste water have not been noted in the literature. Investigation has shown that the degradation of all samples of copolymers in artificial waste water was much faster, where all degradation processes lasted less than a month, than in soil. The results of degradation in soil show that degradation was fastest in soil for cactus growing (for grafted copolymers of polystyrene and starch) and for grafted copolymers of poly(methacrylic acid) and starch in soil for orchid growing. Statistical analysis of data show excellent correlation between degree of degradation and percentage of grafting for graft copolymers of polystyrene and starch and share of starch in copolymers which is necessary to biodegradation started and share of polystyrene in copolymers that prevented biodegradation

Microstructure development and electrical properties of NiO doped alpha-Fe2O3

Poster presented at the 4th Serbian Congress for Microscopy, Belgrade, Serbia, 2010, October 11-12, 201

Supplementary data for article: Nikolić, A. M.; Ajdačić, V.; Opsenica, I. M. Palladium-Catalyzed N-Arylation of 1-Substituted-1H-Tetrazol-5-Amines. Journal of Organometallic Chemistry 2019, 880, 134–142. https://doi.org/10.1016/j.jorganchem.2018.11.007

Supplementary material for: [https://doi.org/10.1016/j.jorganchem.2018.11.007]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3787

Supplementary material for the article: Nikolic, V.; Loncarevic, B.; Popovic, A. Biodegradation of Copolymer Obtained by Grafting Reaction between Methacrylic Acid and Starch. Polymer Bulletin 2019, 76 (5), 2197–2213. https://doi.org/10.1007/s00289-018-2484-x

Supplementary material for: [https://doi.org/10.1007/s00289-018-2484-x]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/341