Radiation sensitive MOSFETs irradiated with various positive gate biases

The RADiation sensitive metal-oxide-semiconductor field-effect-transistors (RADFETs) were irradiated with gamma rays up to absorbed dose of 110 Gy(H2O). The results of threshold voltage, VT, during irradiation with various positive gate biases showed the increase in VT with gate bias. The threshold voltage shift, ΔVT, during irradiation was fitted very well. The contributions of both the fixed traps (FTs) and switching traps (STs) during radiation on ΔVT were analyzed. The results show the significantly higher contribution of FTs than STs. A function that describes the dependence of threshold voltage shift and its components on gate bias was proposed, which fitted the experimental values very well. The annealing at the room temperature without gate bias of irradiated RADFETs was investigated. The recovery of threshold voltage, known as fading, slightly increase with the gate bias applied during radiation. The ΔVT shows the same changes as the threshold voltage component due to fixed states, ΔVft, while there is no change in the threshold voltage component due to switching traps, ΔVst

Farmaceuti i COVID-19 u Srbiji: promocija vakcinacije u javnim apotekama u Republici Srbiji

Uvod i cilj. Pandemija COVID-19 potvrdila je važnost uloge farmaceuta u očuvanju i unap- ređenju javnog zdravlja. Cilj rada je da prikaže aktivnosti farmaceutskih udruženja u Republici Srbiji u promociji vakcinacije. Metode. Savez farmaceutskih udruženja Srbije (SFUS), Udruženje farmaceuta Beograd, Udruženje farmaceuta Vojvodine, Udruženje farmaceuta Zapadne Srbije 1836, Udruženje far- maceuta Nišavsko-pirotskog regiona, Savez privatnih apotekara Srbije i Inicijativa za farma- ciju organizovali su Webinar posvećen ulozi farmaceuta u imunizaciji. Navedena udruženja inicirala su izradu informativne brošure „Covid-19 vakcine u Srbiji”. Brošuru je izradila Katedra za mikrobiologiju i imunologiju Farmaceutskog fakulteta Univerziteta u Beogradu (FFUB) u saradnji sa Agencijom za lekove i medicinska sredstva Srbije. Dizajn brošure uradila je Nacio- nalna Asocijacija Studenata Farmacije – Srbija. Štampanje brošure omogućilo je Ministarstvo zdravlja Republike Srbije u okviru projekta „Hitan odgovor Republike Srbije na COVID-19“. Rezultati. Webinaru održanom 13.02.2021. prisustvovalo je 594 farmaceuta. Brošura je sadržala najznačajnije podatke o COVID-19 vakcinama u Srbiji, ali i odgovore na neka najče- šće postavljana pitanja od strane građana. Napisana je na osnovu najrelevantnijih dostupnih naučnih podataka, a sadržaj je ažuriran tri puta. Brošura je štampana u 150000 besplatnih primeraka i distribuirana u javne apoteke. Apoteke su bile mesto dalje distribucije brošura za- interesovanim pacijentima. Brošura je takođe bila dostupna u e-formatu na sajtu FFUB, SFUS, i na sajtovima brojnih ustanova javnog zdravlja Srbije., a izazvala je i veliko interesovanje u medijima i na društvenim mrežama. Zaključak. Organizacijom webinara, učešćem u izradi i distribuciji brošure o vakcinama, farmaceuti su aktivno učestvovali u informisanju stanovništva, promociji vakcinacije i tako potvrdili značaj farmaceutske zdravstvene zaštite u uslovima pandemije

Hybrid Nanoscale Materials for Convergent Technologies

The convergence of nano-, bio-, and information technologies is based on the understanding of complex hierarchical structures and systems, as well as on the material unity at the nanoscale and on technology integration from that scale. A growing interest in these technologies is a result of their potential to provide solutions to numerous societal challenges, such as advanced healthcare, environmental remediation, sustainable development, and adoption of cyber-physical systems based on the Internet of Things and the Internet of Systems. Taking into account that hybrid nanomaterials possess extraordinary physical and chemical properties derived from their size in the nanoscale, the aim of this work is to present the connection between processing parameters and multifunctional properties of nano scale hybrid materials, focusing on the study of ceramic-polymer structures before they can be nano-engineered into functional devices. The unique functionality of these nanostructures has enabled their applications in numerous devices such as: micro and nano-electro-mechanical systems (MEMS/NEMS), sensors, microactuators, surface acoustic wave devices, polymer electrolyte membrane fuel cells, switches, thermistors, resonators and filters, electrooptic devices, etc. In this study special attention has been paid to their applications in the fields of electronics, biotechnology, environmental protection and remediation

Spectrochemical analysis of four Egyptian Bronze Late Period statuettes

Spektrohemijski su analizirani uzorci sa statuete Ozirisa (sl. 1) iz Muzeja istorije Jugoslavije, inventarski broj 82A. Uzorak la uzet je sa površine statuete, dok je uzorak 1b uzet sa istog mesta, ali na dubini od 2 mm. Dobijeni podaci su približno istovetni, što pokazuje da se u sličnim slučajevima, pri tankom sloju autohtone patine i korozije, bez izražene kalcinacije, uzimanje uzoraka eventualno može vršiti i kroz korozivni sloj bez većeg uticaja na tačnost rezultata. Statueta Ozirisa je urađena od tzv. kalajne bronze, u tehnici punog liva (težina 8,5 kg), osim stopne ploče koja je izvedena u tehnici šupljeg liva. Crnkasta ispuna, uzorak 1s, sastoji se 75 % od silicijum dioksida (SiO2), verovatno sprašenog kvarcnog peska. U produžetku nožnog dela statuete je trn, blago trapezalnog preseka, za uglavljivanje na podlogu. Uzorak 2 potiče sa statuete Neit (sl. 2), iz Gradskog muzeja u Vršcu, inventarski broj Aeg. 27, koja je urađena y punom livu od tzv. olovne bronze. Uzorak 3 je sa statuete Izide koja doji malog Horusa (sl. 3), Narodni muzej u Beogradu, inventarski broj 4/VI, dok je uzorak 4 uzet sa fragmentarnog Horusa (sl. 4), Narodni muzej u Beogradu inventarski broj 6/VI, očito prvobitno dela figuralne kompozicije kurotrofne Izide, slične prethodnoj. Oba predmeta su urađena od tzv. kalajne bronze u tehnici punog liva. Kvalitativna i kvantitativna analiza uzoraka izvršena je emisiono spektrometrijski (iduktivno spregnuta plazma) a dobijeni rezultati prikazani su u tabeli 1. Triangularni Cu-Sn-Pb dijagram (sl. 5) analiziranih uzoraka, zajedno sa uzorcima prethodno publikovane tri statuete Ozirisa (Anđelković, Pavlović and Savović 2002) pokazuje jasno grupisanje. Legura od koje je napravljena prva grupa predmeta (grupacija 1: Oziris, Izida sa Horusom i fragmentarni Horus) sadrži približno 78+7% bakra i malu količinu olova ( lt 4%), dok druga grupa predmeta (grupacija 2: Neit i tri statuete Ozirisa iz Gradskog muzeja u Vršcu) pokazuje niži sadržaj bakra (60±8%), i više olova (12-15%). Prosečan sadržaj kalaja je sličan kod obe trupe ( lt 5%). Statuete se datuju u Pozni period (664-332. godine pre naše ere).The chemical composition of four ancient Egyptian Late Period statuettes (Osiris, Neith, Isis suckling Horus, and fragmentary infant Horus) was determined by inductively coupled plasma atomic emission spectrometry. The results of quantitative analysis demonstrate that three objects are made of a tin bronze, whereas one object is made of a lead bronze. Triangular Cu-Sn-Pb diagram of the four statuettes, along with the additional three Osiris statuettes previously analyzed, shows the grouping among the objects. Sampled core material consisted mainly of SiO2

Spectrochemical analysis and radiographic inspection of metal and core of three Osiris statuettes from the City Museum of Vršac

Spektrohemijski su ispitani uzorci sa tri statuete Ozirisa (sl. 1-3) iz Gradskog muzeja u Vršcu (inventarski brojevi Aeg. 24-26) kupljenih u drugoj polovini 19. veka u Egiptu. Prve dve, šuplje livene, načinjene su u tehnici tzv. izgubljenog voska i kod njih je urađena analiza kako metalnog dela (uzorak 1a, 2a) tako i silikatnog jezgra (uzorak 16, 2b) dok je treća načinjena u punom livu, te je kod nje analizovan samo metal (uzorak 3). Spektrografski je najpre određen kvalitativni sastav (tabela 1), a zatim je urađena kvantitativna spektrometrijska analiza korišćenjem plazme jednosmernog stabilizovanog luka kao ekscitacionog izvora. Dobijeni rezultati pokazuju da metalni deo statueta pored glavnih sastojaka (bakra, olova, kalaja i antimona) sadrži i znatan broj drugih elemenata (tabela 2). Relativno visok sadržaj kalcijuma se može pripisati sloju patine koji nije mogao biti izbegnut pri uzimanju uzorka. Radiografsko ispitivanje na industrijskom rendgenskom uređaju u Zavodu za zavarivanje u Beogradu, pokazuje da je, pored mehaničkih oštećenja, znatan deo metala prve dve statuete prešao u koroziono stanje, dok je treća u potpunosti sačuvana (tab. Ia-c). Materijal kojim su ispunjene statuete sastoji se pretežno od silicijum dioksida (Si02) tj. verovatno sprašenog kvarcnog peska, mada takođe sadrži i znatan broj drugih elemenata. Statuete su izrađene od tzv. olovne bronze. Relativno visok procenat antimona radije se pripisuje nečistoći rude bakra nego namernom dodavanju, dok su olovo i kalaj svakako dodati. Statuete se mogu datovati u Pozni period (sa. 747-332. godine pre naše ere).The composition of ancient Egyptian Oziris statuettes was determined by spectrochemical methods. The results obtained prove that metallic parts of the statuettes were made of an alloy of copper, lead, tin and antimony, which contain minor and trace constituents (Zn, As, Fe, Al, Si, Mg...). Core material of the hollow-casted statuettes consisted mostly of SiO2- The radiographic inspection confirmed a high level of metal corrosion

Pedagogical benefits of fieldwork of the students at the Faculty of Geography in the light of the Bologna Process

Students' opinion and assessment of the quality of teaching presents an important segment of the evaluation of the quality of teaching at university level in accordance with the principles of the Bologna Process. In this study, we have examined opinion of students at the Faculty of Geography, University of Belgrade on the pedagogical benefits of fieldwork, which presents an important determinant of geographers' education. A total of 215 students evaluated pedagogical benefits of fieldwork in relation to didactic-methodical aspects such as: immediate contact with objects of knowledge; interdisciplinary study of a problem; application of various methods of teaching; enhancement of motivation for learning; improvement of social relations, and development of skills necessary for fieldwork. Research results indicate that students recognize and positively evaluate benefits of fieldwork. Final-year students as well as students who had more days of fieldwork evaluate benefits of fieldwork in a more positive way. Research results indicate the need to improve the quality of fieldwork and increase its share in the curriculum of the Faculty of Geography in accordance with the constructivist paradigm in education, which places a student at the centre of educational process, and fundamental principles of the Bologna Process

A comparative analysis of plant growth- -promoting traits of Pseudomonas and Bacillus strains isolated from Lolium perenne rhizospheric soil in Vojvodina (Serbia) and their effect on the plant yield

The objective of this work was to do a comparative study of Pseudomonas and Bacillus isolates for their plant growth-promoting (PGP) potential, monitoring the impact of selected isolates on the yield of English ryegrass (Lolium perenne). Isolation, physiological and biochemical characterization, in vitro assay of enzymatic and plant-growth promoting activities of isolates were done. Pseudomonas isolates have been shown to have the ability to use different sources of carbon, to live in the condition of low pH as well as temperature and to produce siderophore. On the other hand, Bacillus isolates have the ability to solubilize phosphate, to produce a greater amount of indol-3-acetic acid (IAA) than Pseudomonas isolates and have an inhibitory effect on the growth of phytopathogenic fungi. In other investigated traits, isolates were similar. The use of Pseudomonas sp. P12 and Bacillus sp. B1 isolates had a positive effect on the plant mass and total yield, which indicate that the use of these isolates can result in a better yield of forage crops

A study of the structural and morphological properties of Ni-ferrite, Zn-ferrite and Ni-Zn-ferrites functionalized with starch

Zinc-ferrite, nickel-ferrite and mixed nickel-zinc ferrites were successfully synthesized via the thermal decomposition method from acetylacetonate complexes. To control the particle size and enhance dispersibility in an aqueous medium, starch, a natural and biocompatible compound, was used for the first time for coating such magnetic powders. X-ray powder diffraction (XRPD) was performed to study the structural properties of all samples. The presence of a single-phase spinel structure as well as the cation distribution in both sites of all investigated magnetic powders was confirmed. The values of unit cell parameters obtained from the results of the Rietveld analysis decreased, while the average crystallite size increased with increasing Ni2+ content. The average microstrain parameters unambiguously showed a change in the spinel structure with cation distribution. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) analyses were also utilized to characterize the synthesized materials, corroborating the XRPD data. The obtained results indicated that functionalization by starch was successfully achieved.Peer-reviewed article: [http://cherry.chem.bg.ac.rs/handle/123456789/3149

Effect of nitrogen fertiliser and lime on the floristic composition, soil microbes and dry matter yield of danthonietum calycinae grassland

© 2019 Academic Press. Natural grasslands are significant resources for forage production, which is not exploited enough, mostly because of low production, as a result of bad grasslands management. The research has been carried out on the association Danthonietum calycinae to evaluate the effects of different nitrogen application rates (N20, N80 and N140) and lime (1 tha-1) on the floristic composition, soil microbes and dry matter yield. Botanic composition was strongly influenced by the treatments, especially by N applications. Nitrogen fertilisation led to significant increase of grass species in the association (from 57% to 82%), while higher rate of nitrogen caused a significant decrease of plants from other families (especially legumes). Application of low and medium rate of nitrogen positively effect on microbial abundant in soil, but the highest dose (140 kg N) reduced all microbial count, except fungi. Mineral nitrogen fertilisation had a favourable effect on dry matter yield in all treatments. The highest increase in dry matter yield relative to the control was in N140 treatments (6.66 t ha-1). Results indicated that optimal applications of nutrients for this association is application of PK and lime and 80 kg of nitrogen which enable high yield (6.38 t ha-1) in comparison with control (3.16 t ha-1) and preserving soil fertility and the environment at the same time

Sensitivity of Unbiased Commercial P-channel Power VDMOSFETs to X-ray Radiation

The effect of X-rays on the p-channel power vertical double diffused metal-oxide-semiconductor field-effect transistors (VDMOSFETs) was investigated. The VDMOSFETs were irradiated without gate polarization using three different Xray beams. Due to the polyenergetic nature of X-rays, their effect is much more complex than the effect of gamma radiation on transistors. The influence of X-rays on threshold voltage shift $(\Delta V_T)$ and on the creation of fixed traps (FTs) in gate oxide and on switching traps (STs) near and at oxide/semiconductor interface was analyzed. The effect of STs on T is more significant than in the case of y-radiation. The obtained results showed that the sensitivity to radiation depends on the radiation energy, and they are in accordance with the theoretical predictions