THE ROLE OF RENEWABLE ENERGY SOURCES IN FUTURE ELECTRICITY SUPPLY

Članak se bavi ulogom obnovljivih izvora energije u opskrbi električnom energijom. Izvorni razlog za njihovo uvođenje i razvoj bio je stvaranje protuteže porastu stvaranja stakleničkih plinova koji nastaju pri proizvodnji električne energije iz fosilnih goriva. Europska unija predstavlja najbolji primjer delegirane politike i propisa koje zakonodavci i vlade prikladno tumače. Zakoni na području energije i okoliša usvojeni u Republici Hrvatskoj približili su se europskom zakonodavstvu, s ciljem integriranja Republike Hrvatske u untarnje europsko tržište električne energije i Europsku uniju.This article deals with the role of renewable sources in the electricity supply industry. The original reason for their introduction and development was to help offset the rise in the production of greenhouse gases due to electricity genaration from fossil fuels. The EU represents the best example of federally delegated policy and regulation interpreted differently by national regulators and goverments. The laws in the area of energy and the environment enacted by the Republic of Croatia have been approximated to the European legislation in order for the Republic of Croatia to be integrated in the internal market and EU

Error Probability in Redundant Packet Sending over IP Network

In this paper we calculate error probability of packetized signal when method of redundant packet sending is used in IP network. The number of repeated signaling packets from each interval of packetization is determined to achieve the desired error probability. The method for management of this number of repetitions is developed based on the new analysis. This method is especially important in the case of sending signaling criteria of classic telephony network over IP network, because it makes possible to reach the same error probability as in classic telephony network

BIODIESEL AS ALTERNATIVE ENGINE FUEL

Gotovo sve zemlje Europske unije, a i većina zemalja u tranziciji u posljednjem su desetljeću, a neke i ranije, pokrenule proizvodnju biogoriva i to biodizelskoga goriva i etanola. Na temelju pregleda brojnih rezultata istraživanja u svijetu, u ovom se radu analiziraju najvažnija svojstva biodizelskoga goriva, njegova dosadašnja primjena kao alternativnog goriva za dizel motore, te utjecaj njegova sagorijevanja na okoliš u odnosu na mineralno dizel gorivo. Kako je osnovna sirovina za proizvodnju biodizela iz obnovljivih resursa ulje uljane repice, detaljno se analizira postojeća struktura sjetve i udio uljane repice na obradivim površinama u Hrvatskoj, te realne mogućnosti proizvodnje ove kulture za neprehrambeni lanac, odnosno mogućnosti proizvodnje biodizela u Hrvatskoj.Practically all the countries in the European Union and most of the transition countries have in the last decade, and some even earlier than that, started off the production of biofuels, that is, of biodiesel fuel and ethanol. On the basis of a survey of numerous results of investigations in the world, in this work the most important properties of biodiesel fuel are reviewed, its employment to date as alternative fuel for diesel engines, and the environmental impact of its combustion as compared with that of mineral diesel fuel. Since the basic raw material for the production of biodiesel from renewable resources is the oil of oilseed rape, a detailed analysis is given of the existing structure of the crop and the percentage of the cultivable land in Croatia given over to oilseed rape, as well as the realistic opportunities for the production of this crop for the non-food chain, in other words, the opportunity for the production of biodiesel in Croatia

Composite bosons in bilayer nu = 1 system: An application of the Murthy-Shankar formalism

We calculate the dispersion of the out-of-phase mode characteristic for the bilayer nu = 1 quantum Hall system applying the version of Chern-Simons theory of Murthy and Shankar that cures the unwanted bare electron mass dependence in the low-energy description of quantum Hall systems. The obtained value for the mode when d, distance between the layers, is zero is in a good agreement with the existing pseudospin picture of the system. For d nonzero but small we find that the mode is linearly dispersing and its velocity to a good approximation depends linearly on d. This is in agreement with the Hartree-Fock calculations of the pseudospin picture that predicts a linear dependance on d, and contrary to the naive Hartree predictions with dependence on the square-root of d. We set up a formalism that enables one to consider fluctuations around the found stationary point values. In addition we address the case of imbalanced layers in the Murthy-Shankar formalism.Comment: 10 pages, 1 figur

Leaching kinetics of Co(II) and Sr(II) contaminated soil via chemical extraction method

Artificially contaminated soil, with mixture of Co(II) and Sr(II) ions in different proportions, was tested. The main aim was to investigate the possibility of ethylenediamine-tetraacetic acid (EDTA) utilization in the chemical extraction process as a method for soil remediation in the case of mixed contamination. The efficiency of this process when EDTA of 10 -4 molL -1 was used was low, while the application of the EDTA solution of the initial concentration 5 · 10 -3 molL -1 or higher showed almost the same efficiency. This suggested that the application of the solution EDTA (5 · 10 -3 molL -1 ) is optimal from the aspect of cost and degradation of soil properties. Furthermore, process kinetic was fitted using one parameter shrinking core models. Kinetic data modeling showed that the process is complex, demanding multi resistance kinetic model. © 2018, Vinca Inst Nuclear Sci. All rights reserved

Leaching kinetics of Cs+ and Co2+ under dynamic conditions

The possibility of retaining Cs+ and Co2+ bound by immobilization processes in the cement matrix is defined as the subject of its investigation: the cement matrix formulation, the water/ cement ratio, the amount of waste, and the porosity of such a structure. Implementing the standard leaching method by Hespe the possibility of comparing different authors’ results was achieved. Diffusion and semi-empirical model were used to investigate the transport phenomenon in order to predict the leaching level for a long period of time. Leaching of Co2+ and Cs+ ions under dynamic conditions immobilized in the cement matrix dynamic conditions decreases with the increase of the sludge content, regarding porosity increase. The effects of the diffusion and surface washing are equalized, and the contribution ofthe matrix dissolution to the Cs + and Co2+ transport in the cement porous media increases, on average, for one order of magnitude. The semi-empirical model gives a better approximation for Co2+ and Cs+ leaching process for the duration ofthe experiment while both models significantly approximate leaching results in dynamic conditions. © 2019, Vinca Inst Nuclear Sci. All rights reserved

Radioactive waste management in health care institutions

Institucije zdravstvene zaštite sve više primenjuju radioizotope u dijagnostičke i terapeutske svrhe, posebno u kardiologiji i onkologiji. Sve ovo dovodi do povećanja količine radioaktivnog otpada. Bezbedno odlaganje neiskorištenog radioaktivnog materijala i predmeta kontaminiranih istim predstavlja vitalnu komponentu sveobuhvatne strategije upravljanja. Osnovni cilj bezbednog odlaganja radioaktivnog otpada je da izlaganje zračenju ljudi, profesionalnih lica i životne sredine ne pređe propisane granice kroz institucionalni koordinisani napor u nacionalnom pravnom okviru. U ovom radu data je kategorizacija pomenutog otpada, načini segregacije, vrste tretmana, kao i načini odlaganja različitih vrsta otpada nastalih u ustanovama zdravstvene zaštite.The health care institutions use radioisotopes for diagnostic and therapeutic purposes, especially in cardiology and oncology, and contribute to the formation and accumulation of radioactive waste. Safe disposal of unused radioactive material and contaminated objects is of the vital importance for comprehensive management strategy. The main aim of the safe disposal of radioactive waste is to prevent the radiation exposure of professionally exposed personnel and the environment over the prescribed limits, through institutionally coordinated efforts based on the national legal framework. This paper represents a review of categorization, segregation, treatment and proper disposal of different radioactive wastes created in the health care institutions.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

The politics of performance: transnationalism and its limits in former Yugoslav popular music, 1999–2004

This paper examines transnational relations between the Yugoslav successor states from the point of view of popular music, and demonstrates how transnational musical figures (such as Djordje Balaševi?, Mom?ilo Bajagi?-Bajaga and Ceca Ražnatovi?) are interpreted as symbolic reference points in national ethnopolitical discourse in the process of identity construction. Another symbolic function is served by Serbian turbofolk artists, who in Croatia serve as a cultural resource to distance oneself from a musical genre associated by many urban Croats with the ruralization (and Herzegovinization) of Croatian city space. In addition, value judgements associated with both Serbian and Croatian newly composed folk music provide an insight into the transnational negotiation of conflicting identities in the ex-Yugoslav context. Ultimately the paper shows how the ethnonational boundaries established by nationalizing ideologies created separate cultural spaces which themselves have been transnationalized after Yugoslavia's disintegration