Feasibility study of a current mode gamma radiation dosimeter based on a commercial pin photodiode and a custom made auto-ranging electrometer

An experimental study has been conducted to evaluate the feasibility of a current mode gamma radiation dosimeter, consisting of a commercial PIN photodiode as a radiation sensor, and a custom made auto-ranging electrometer for real-time measurement of the PIN photodiode’s response under radiation exposure. The radiation induced direct current response for single PIN photodiodes with different active areas, as well as for multiple PIN photodiodes connected in parallel, has been investigated. Three types of commercial silicon PIN photodiodes have been chosen for evaluation - S1223, BPW34, and PS100-6-CER2 PIN. During the experiment, five samples have been tested - three samples made of single PIN photodiodes (one sample of each photodiode type) and two samples formed by connecting multiple photodiodes in parallel (two BPW34 photodiodes in parallel and four BPW34 photodiodes in parallel). The samples have been irradiated with a 60Co gamma ray source and the relations between the induced photocurrent and the dose rate, and between the accumulated charge and the absorbed dose, have been determined. For measuring the photodiodes response, a custom made auto-ranging electrometer controlled by a personal computer, and capable of measuring direct currents from 50 pA to 10 mA with relative error less than 2.5%, has been used. Obtained results have shown very good linearity between the dose rate and the induced photocurrent for dose rates ranging from 0.93 Gy/h to 67 Gy/h. Also, very good linearity has been observed between the accumulated charge and the absorbed dose for all tested samples, within the investigated range of absorbed doses from 472 mGy to 3.3 Gy. On the basis of the obtained results, a simple model has been derived, enabling the estimation of the photodiode’s current response as a function of the dose rate and the photodiode’s geometry (active area and depletion layer width). [Projekat Ministarstva nauke Republike Srbije, br. 43011

Thermal extras of vegetation walls in Belgrade climatic conditions

The goal of this research is to analyse the possibility of using vegetation walls in order to improve the thermal characteristics of office buildings in Belgrade's climatic conditions. The study analyses the possibility of integrating vegetation modules into the fa ades of office buildings. The paper shows the potential of vegetation technologies in the realisation offacade coverings of architectural buildings with a goal to reduce heat gained during summer time. The use of vegetation walls in architecture has opened up new planning possibilities and created planning conditions for reducing the energy necessary for cooling office buildings. Considering that interaction between the outer environment and inner solving the dependency between comfort, outer look and building's energy balance. This paper is presenting the possibility of using sustainable technologies for solving the problem of overheating in Belgrade's climatic conditions. The research considers the possibilities of using vertically greening systems in planning facade coverings, with an analysis of their thermal characteristics for climatic conditions in Belgrade

Terminology of management - a contribution to the development of terminology and language policy and palnning ; Терминология менеджмента - в поддержку развития терминологической и языковой политики и планирования

Предмет истраживања ове докторске дисертације је терминологија научне и стручне области менаџмента на српском језику у контексту терминолошке и језичке политике и планирања и менаџмента терминологије...The research topic of this doctoral dissertation is terminology of the scientific and professional subject-field of management in the Serbian language in the context of the terminology and language policy and planning, and terminology, management..

The meaning (and consequences) of using a photograph of a Holocaust victim's body in a fashion magazine

Primarna namera ovog istraživanja ogleda se u iznalaženju i raskrivanju smisla fotografija mrtvih, izgladnelih i unakaženih tela žrtava Holokausta u modnom magazinu „Vogue” (izdanje iz 1945. godine), te i posledica koje su se, iz toga, vremenom razvile. Kroz rad ćemo, prateći način odnošenja prema telu žrtve kroz decenije koje su usledile nakon ratne katastrofe, sagledavati i kako je, duboko skriven ispod denotativnog, ko- notativni semantički i smisaoni potencijal tih fotografija izbio na kulturno-diskurzivnu površinu i postao deo konstituisanja posthumanističkog principa odnošenja prema biću. U toj ćemo nameri poći od načina na koji se fotografija odnosi prema stvarnosti, te, shodno Virilioovoj, Bartovoj i Fluserovoj demistifikaciji fotografskog okulara, doći do zaključaka povodom uticaja slike tela žrtve u modnom magazinu na način poimanja Holokausta danas.The primary purpose of this research is to find and reveal the meaning of photographs of dead, starved and disfigured bodies of Holocaust victims in “Vogue” fashion magazine (edition from 1945), and the consequences that developed over time. Through the work, following the manner of treating the victim's body through the decades that followed the war disaster, we will look at how, deeply hidden under the denotative, connotative semantic and meaningful potential of those photographs, emerged the cultural and discursive surface and became part of the constitution of the post-humanist principle of treatment towards being. With that intention, we will start from the way photography relates to reality, and, according to Virilio's, Barth's and Flusser's demystification of the photographic eyepiece, reach conclusions regarding the influence of the image of the victim's body in a fashion magazine on the way the Holocaust is understood today.Zbornik je rezultat istraživanja u okviru Studija Holokausta koje se pod pokrovitelјstvom Claims Conference (Conference on Jewish Material Claims Against Germany) izvode na Univerzitetu u Kragujevcu

Application of Predictive Models for Natural Gas Needs - Current State and Future Trends Review

Nowadays, in terms of trading on the world scale, to foresee a natural gas consumption represents an essential activity. In the first part, the paper examines the current state of the Serbian natural gas sector and methodology applied for prediction and capacity planning. In addition, the study intends to give a comprehensive assessment of predictive algorithms for natural gas needs involved in the last decade with projections and suggestions for future applications. The primary task is to evaluate used predictive models with an emphasis on the accuracy of the predictions obtained. Additionally, the paper will analyse used parameters, consumption scale, prediction scope, forecast algorithms, and other related information. The main objective of this study is to review the new-fangled information related analyses data from peer-reviewed journals, international conferences, and books

Leaching of chromium from chromium contaminated soil: Speciation study and geochemical modeling

Distribution of chromium between soil and leachate was monitored. A natural process of percolating rainwater through the soil was simulated in the laboratory conditions and studied with column leaching extraction. Migration of chromium in the soil is conditioned by the level of chromium soil contamination, the soil organic matter content, and rainwater acidity. Chromium (III) and chromium(VI) were determined by spectrophotometric method with diphenilcarbazide in acidic media. Comparing the results of chromium speciation in leachate obtained by experimental model systems and geochemical modelling calculations using Visual MINTEQ model, a correlation was observed regarding the influence of the tested parameters. Leachate solutions showed that the concentration of Cr depended on the organic matter content. The influence of pH and soil organic matter content is in compliance after its definition through experimental and theoretical way. The computer model - Stockholm Humic Model used to evaluate the leaching results corresponded rather well with the measured values

Band flattening in buckled monolayer graphene

The strain fields of periodically buckled graphene induce a periodic pseudo-magnetic field (PMF) that modifies the electronic band structure. From the geometry, amplitude, and period of the periodic pseudo-magnetic field, we determine the necessary conditions to access the regime of correlated phases by examining the band flattening. As compared to twisted bilayer graphene the proposed system has the advantages that: 1) only a single layer of graphene is needed, 2) one is not limited to hexagonal superlattices, and 3) narrower flat bandwidth and larger separation between flat bands can be induced. We, therefore, propose that periodically strained graphene single layers can become a platform for the exploration of exotic many-body phases.Comment: To appear in Physical Review

Uticaj agroekoloških uslova i hibridne kombinacije na klijavost semena kukuruza

Germination energy and seed germination of four maize combinations cultivated under different growing conditions were observed. Analysis of hybrid seed of four commercial combinations derived at the Maize Research Institute, Zemun Polje, grown in three locations, were done on the working sample of 4 x 100 seeds under laboratory conditions. The experimental data was processed for the mean and total variability (X and C.V.) for both seed traits and for each test variant. The total average values of germination energy and germination in the period of investigation amounted to 94.5% and 94.8%, respectively. The coefficient of variation for germination energy was 0.67%, while for germination it was 0.39%. In the five-year study, the hybrid combination ZP704 had the highest values of germination energy (95.9%) and total germination (96.3%).Test results indicate that coefficients of variations for both observed traits over years were low, which points out to homogeneity of the material. Significant effects of factors (hybrid and location) and their interaction on observed seed properties were established by the analysis of variance. Gained results indicate that all four hybrids had high level of expression of traits under changeable agroecological conditions, as well as, a great effect of factors (hybrid and location) on germination energy and seed germination.U ovim istraživanja proučavane su energija klijanja i klijavost semena kukuruza četiri genotipske kombinacije u različitim agroekološkim uslovima uspevanja. Analize hirbidnog semena četiri komercijalne kombinacije Instituta za kukuruz Zemun Polje, proizvedene na tri lokaliteta, urađene su u laboratorijskim uslovima na radnom uzorku 4 x 100 semena. Eksperimentalni podaci obrađeni su na srednju vrednost i ukupnu varijabilnost (X i C.V.) za obe osobine semena i svaku varijantu istraživanja. Ukupna prosečna vrednost energije klijanja u posmatranom periodu bila je 94.5%, a klijavost 94.8%. Koeficijent varijacije za energiju iznosio je 0.67%, a za klijavost 0.39%. Hibridna kombinacija ZP704 u petogodišnjim istraživanjima imala je najviši nivo energije klijanja (95.9%) i ukupne klijavosti (96.3%). Rezultati testova ukazuju da koeficijenti varijacije ispitivanih karakteristika kod obe osobine su mali i ukazuju na homogenost materijala. Dvofaktorijalnom analizom varijanse utvrđen je značajan uticaj faktora (hibrid i lokacija), kao i njihova interakcija na ispitivane osobine semena. Dobijeni rezultati pokazali su da sva četiri hibrida imaju visok nivo ispoljavanja ispitivanih osobina u promenljivim agroekološkim uslovima, kao i visok uticaj faktora ( hibrid i lokalitet) na energiju i klijavost semena

Ekstrakcija, karakterizacija, biološka aktivnost i potencijalna primena fenolnih jedinjenja iz plodova i lišća biljnih vrsta familija Rosacae, Cornacae i Grossulariaceae

In this doctoral dissertation we optimization conventional and ultrasonic exstraction techniques in with the aim of obtaining biologically active phenolic compounds from the berries and leaves of plants families Rosaceae, Cornaceae and Grossulariacae. Phenolic content of the obtained extracts were subjected to UV-Vis and HPLC analyzes. The significant antioxidant and antimicrobial activity was confirmed. In terms of their possible practical applications performed most active inclusion complexation of phenolic compounds in extracts type cyclodextrin. Characterization of the obtained inclusion complexes were determined by the method of spectral analysis (FT-IR, NMR, XRD). Based on these results it can be concluded that fruits and leaves of plants families Rosaceae, Cornaceae and Grossulariaceae can find great application in the food and cosmetics industries as well as in pharmacy