Application of CR-39 detector in neutron detection and dosimetry

A comparison of experimental and calculated responses of a CR-39 detector to neutron spectra from an Am–Be source is presented in this paper. A computer program called Neutron_CR-39.F90 for neutron simulation through a CR-39 detector and its detection was described and developed. The secondary particles are created in different directions and their latent tracks are oriented randomly within the detector. Some tracks will be etched from the point where the particle was created in the direction of the particle motion – this is direct etching. Other tracks will be etched from the point where the particle was stopped or from where it exited from the detector, in an opposite direction to the particle movement – this is the etching in a reverse direction. In this paper a calculation of the track walls etched in the same and opposite directions is described by using Newton’s method. The program Neutron_CR-39.F90 contains subroutine Neutron.f90 for neutron simulation and subroutines Trackfdmsame.f90 and Trackfdmback.f90 for the calculation of created track profiles after detector etching in the same and reverse direction, respectively. Developed program has been used to calculate the neutron dose equivalent rate for the CR-39 detector as well as the track density. Conversion coefficient (sensitivity) between track density in track/cm2 and neutron dose equivalent in mSv, was calculated by using above mentioned program. It has been found that sensitivity increases linearly with removed layer in the investigated range between 6 mm and 24 mm. The neutron equivalent dose rate was measured by an active device, and compared with the calculated one. Good agreement was found between these two independent techniques for equivalent dose determination. The mean neutron fluence to dose equivalent conversion factor, hφ, was determined also, and it is in good agreement with previously published results (Burger and Schwaster, 1988; ISO/DIS 8529, 2000). Experimental and theoretical results, and their agreement, suggest the potentiality of a CR-39 detector for fast neutron dosimetry

Energy window of Makrofol for alpha particle detection

© 2019 Elsevier B.V. Detection energy window of Makrofol detector irradiated with alpha particles and chemically treated by PEW (potassium hydroxide, ethanol, water) solution was investigated. Detectors were exposed to 241Am source through the cylindrical collimators in order to control incident alpha particle energies and angles. Alpha particles were detected in the wide energy range from 0.4 MeV to above 5 MeV. The dependence of track diameter on particle incident energy was also examined. Changes of etchant concentration and bulk etch rate (Vb) during two-hour etching were investigated. A slight increase of etchant concentration was observed while Vb was nearly constant during the whole etching process. Alpha particle passage through collimators with various dimensions and the corresponding energy distribution were also simulated theoretically using Monte Carlo Method and computer program written in Fortran90

Slovenians in Serbia: Bibliography with Annotations

Bibliografija o Slovencima u Srbiji predstavlja informativnu bibliografiju sa ciljem da pruži široj stručnoj i čitalačkoj javnosti saznanja o slovenačkoj populaciji, koja više od stopedeset godina, boravi i živi u Srbiji. Reč je o jedinstvenoj bibliografiji, čiji predmet nije isključivo obrada kompletne izdavačke delatnosti Slovenaca u Srbiji, već sakupljanje, sistematizovanje i anotiranje bibliografskih jedinica relevantnih, pre svega, za naučni rad. Bibliografija obuhvata reference iz oblasti etnologije, istorije, književnosti, leksikografije, muzikologije, demografije, geografije i dr.The bibliography of Slovenians in Serbia is an informative bibliography with the aim of providing the broader expert and reading public with information about the Slovenian population, who has been living in Serbia for over 150 years. It is a unique bibliography. The subject of this bibliography is not only the processing of the entire publishing activity of Slovenians in Serbia. Bibliography including the collection, systematization and annotation of bibliographic units relevant, above all, for scientific work. The bibliography includes references in the fields of ethnology, history, literature, lexicography, musicology, demography, geography, etc

New economic development model as an improving factor of Serbian economy's competitiveness

The paper has three chapters. In the first chapter we define the competitive position of the Serbian economy utilizing the Index of global competitiveness, in order to underline the areas where the positions of Serbia are satisfied vs ones that need improvement. In the second chapter of the paper we analyze imperfections of present economic development policy of Serbia. In the third part of the paper we are presenting basic recommendation and guidelines for the future export-based economic development model that would improve the competitive advantages of Serbian economy

Innovative modifications of graphene quantum dots for improved photodynamic therapy in antibacterial treatment

Considering the rising concern of antibiotic resistance, developing advanced antibacterial solutions is highly needed. The ability of graphene quantum dots (GQDs) to generate reactive oxygen species (ROS) upon light exposure made them promising candidates as agents in photodynamic therapy for combatting infections, including antibiotic-resistant strains. GQDs show versatile chemical, physical, and biological properties such as high fluorescent activity, resistance to photo-bleaching, low toxicity, excellent solubility, and biocompatibility. This research focused on exploring the ability of GQDs to produce singlet oxygen under blue light exposure. We used two singlet oxygen probes, 9,10-anthracenediylbis(methylene) dimalonic acid and 1,3-diphenylisobenzofuran to study photoinduced production radicals from several GQDs. To tune the ability of GQDs to generate ROS, we used gamma irradiation in two different media, the presence of L-cysteine and cyclopentanone. The results showed improvements in singlet oxygen production in both cases. However, the modification conducted with cyclopentanol showed notably higher efficacy in promoting singlet oxygen production. This research demonstrates the increasing significance of GQDs in discovering new methods to combat bacteria. The modification of GQDs with gamma irradiation leads to increased production of singlet oxygen enhancing the effectiveness of photodynamic therapy for treating infections.Twenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi

Activities of Slovenian associations in Belgrade (1921-2014)

Slovenians have lived for centuries in the territory of the Republic of Serbia. Between the 16th century and the mid-19th century, they took part in wars and battles for the liberations of Serbia and Belgrade, mainly as individuals. In the second half of the 19th century, a more massive immigration of Slovenian population in the territory of the present-day Serbia took place and this trend reached its peak at the beginning of World War II, when about 10,000 Slovenians were forced to settle there as refugees. Also, in the post-war period, a large number of Slovenians settled in Serbia, especially in Vojvodina, as part of a planned colonization scheme. Although a certain number of them returned to Slovenia, a majority decided to stay in the territory of Serbia and started a new life there. In the new environment, temporary or permanent, Slovenians began to organize their life. They adjusted themselves to the lifestyle of their new living environment, but they also organized themselves into associations, through which they maintained contacts with their homeland. By the 1990s, the Slovenian population in Serbia mainly lived intermingled with other nations from the common state, SFR Yugoslavia. After the dissolution of Yugoslavia and the formation of independent states, Slovenians in Serbia became an ethnic minority and they began to establish their associations upon different bases. Based on archival data, literature and papers resulting from research projects conducted by Serbian and Slovenian scholars, as well as results of their joint research, the paper deals with Slovenians in Belgrade and their associations since the second half of the 19th century until the present day. Having in mind the ongoing research on the Slovenians in the territory of Serbia and an easier access to data on associations established since 1997, this study particularly focuses on Slovenian associations that used to be active in the past but ceased to exist.U radu se govori o beogradskim Slovencima i njihovim udruženjima od početka 20. veka do danas, na osnovu podataka iz arhivske građe, literature, objavljenih istraživačkih radova na projektima srpskih i slovenačkih naučnika i rezultata zajedničkog istraživanja. S obzirom na aktuelna istraživanja o Slovencima na teritoriji Srbije i lakšu dostupnost podataka o društvima formiranim od 1997. godine nadalje, u radu je veća pažnja posvećena slovenačkim društvima i njihovoj delatnosti, koja su postojala u ranijem periodu i koja više ne postoje.Tema broja : Udruženja nacionalnih manjina Srbij

Deset desetercev Janeza Vrhovca

Janez Vrhovec, rođeni Beograđanin slovenačkog porekla, u javnosti je poznat kao jedan od najvećih jugoslovenskih i srpskih posleratnih filmskih i televizijskih glumaca, koji je tokom više od četiri decenije odigrao preko dve stotine uloga u domaćim, stranim i koprodukcionim filmovima, kao i u TV serijama. Bio je prvi glumac sa statusom slobodnog filmskog umetnika u Jugoslaviji. Verovatno je manje poznato da je Janez Vrhovec, takođe, pedesetih godina prošlog veka bio autor na desetine tekstova pisanih u obliku deseterca, a za emisiju „Veselo veče“ Radio Beograda – kultnu emisiju koja je više od pedeset godina, svake nedelje uveče, zabavljala jugoslovensku slušalačku publiku. U prilogu teksta objavljeno je deset deseteraca, pet - prvi put

Brain metastases of choriocarcinoma: A report on two cases

Introduction. Gestational trophoblastic diseases (GTD) are a spectrum of tumors with a various of biological behavior and potential for metastases. It consists of hydatiform mole, invasive mole, choriocarcinoma and placental site trophoblastic tumor. Choriocarcinoma presents a very aggressive tumor with high malignant potential. Case report. We presented the two cases of choriocarcinoma with brain metastases. The first one was manifested by neurological deterioration as the first sign of metastasis, while the second patient had firstly metrorrhagia and in the further couse neurological disturbances that suggested the presence of brain tumor. In both cases we applied a combined treatment of surgery, chemotherapy and radiation therapy. Both patient survived with high quality of life. Conclusion. A successful outcome of brain metastases of choriocarcinoma was obtained by the use of a combined treatment of surgery, chemotherapy and radiation therapy. In cases of young women with brain metastases, gynecological malignancy should be always considered

Libraries of Research Institutes and Organizations: Legislative Framework and Practice

U Srbiji postoji više od 70 akreditovanih naučnih instituta, ustanova i centara izuzetnih vrednosti, sa bibliotekama čiji knjižni fondovi često premašuju fondove fakultetskih biblioteka, sa bibliotekarima i knjižničarima čiji je rad integrisan u stručnu i naučnu produkciju srpskih naučnika, kao i u promociju njihovog naučnog rada i izdavačke delatnosti instituta. Delatnost ovih biblioteka odvija se u procepu između dva ministarstva i dva zakona (Zakon o bibliotečko-informacionoj delatnosti, za čije je sprovođenje zaduženo Ministarstvo kulture i informisanja Republike Srbije i Zakon o naučnoistraživačkoj delatnosti Ministarstva za prosvetu, nauku i tehnološki razvoj), a stručnjaci koji u njima rade nisu ni u jednom dovoljno definisani, niti pak adekvatno priznati i nagrađeni. U radu se analizira zakonska regulativa relevantna za delatnost ovih biblioteka, a ukazuje se i na probleme vezane za organizaciju rada i status bibliotečkih radnika koji su posledica nedorečenih propisa i/ili nedosledne primene zakonom predviđenih rešenja, kao i na nemogućnost uključivanja u sistem uzajamne katalogizacije. Rad govori i o osnivanju Sekcije bibliotekara i knjižničara, strukovnog udruženja koje u okviru Zajednice instituta Srbije aktivno učestvuje u unapređenju bibliotečko-informacione delatnosti i širenju svesti o značaju biblioteka i bibliotekara naučnih instituta i ustanova i njihovom očuvanju. U zaključnim razmatranjima ponuđeni su predlozi za rešavanje postojećih problema i poboljšanje statusa bibliotečkih radnika zaposlenih u naučnoistraživačkim institutima i ustanovama.In Serbia, there are more than seventy accredited research institutes, organizations and centers of excellence. In terms of size, the book holdings of their libraries often exceed those of academic libraries. However, work of their library staff is incorporated in the research output of Serbian scholars and the promotion of their scientific work and publications. Activities of these libraries are distracted between two ministries and two laws (the Law on Library and Information Science Activities, enacted under the auspices of the Ministry of Culture and Information of the Republic of Serbia and the Law on Scientific Research, enacted under the auspices of the Ministry of Education, Science and Technological Development of the Republic of Serbia). The status of library professionals working at these institutes is neither precisely defined nor adequately recognized and rewarded in any of these sectors. The paper analyzes the legal framework relevant to the activity of the libraries of research institutes and the problems related to the organization of work and the status of library professionals that arise from the vagueness of legislation and/or inconsistent implementation of the legislative solutions. It also explains why it is impossible for most research libraries to join the collaborative cataloguing system. The paper deals with the establishment of the Librarians’ Section of the Serbian Association of Institutes, a professional association striving to improve library and information services and raise the awareness about the importance and survival of libraries and librarians at research institutes. In the concluding remarks, the authors present possible solutions to the problems and suggest ways to improve the status of library workers at research institutes and organizations