The article discusses the question of energy production from nuclear sources considering the growing demand for energy worldwide, the advantages and disadvantages of using nuclear energy. ...International Atomic Energy Agency (IAEA) promotes the peaceful use of nuclear energy, and the State Office for Radiological and Nuclear Safety (DZNRS) monitors the use of ionizing radiation sources in Republic of Croatia. Paper describes the role of the IAEA technical cooperation program involving Croatia (INT9173 "Training in Radioactive Waste Disposal Technologies in Underground Research Facilities - URFs"). The importance of the involvement of Croatian scientists and experts, in the said project of technical cooperation in the field of radioactive waste management, is presented through activities conducted during the period since 2009 to date, taking into account Croatia's obligations regarding the disposal of radioactive waste generated by operation of the nuclear power plant Krsko. PUBLICATION ABSTRACT
Full text
Available for:
CEKLJ, NUK, ODKLJ, UL, UM, UPUK
Coronary artery disease is an important complication of hypertension. Therefore, the effects of antihypertensive therapy on the endothelial nitric oxide (NO)/L-arginine pathway and vascular smooth ...muscle were studied in left anterior descending coronary arteries of Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Angiotensin II (AT1) receptor antagonists CGP 48369 and valsartan, angiotensin-converting enzyme inhibitor benazepril HCl, and calcium antagonist nifedipine were used as antihypertensive agents.
Rings were examined in myograph systems for isometric tension recording. In untreated WKY and SHR rings, acetylcholine (10(-9) to 10(-5) mol/L) but not bradykinin, substance P (both 10(-6) mol/L), or thrombin (1 U/mL) induced comparable endothelium-dependent relaxations. These relaxations were markedly decreased by NG-monomethyl-L-arginine (10(-4) mol/L) and fully prevented by N omega-nitro-L-arginine methyl ester (10(-4) mol/L) or methylene blue (10(-5) mol/L). In vitro treatment of WKY and SHR rings with benazeprilat, CGP 48369, or valsartan (3 x 10(-7) mol/L) did not affect responses to acetylcholine. In SHR, chronic therapy for 8 weeks with benazepril HCl, CGP 48369, valsartan, or nifedipine (each 10 mg.kg-1.d-1 PO) similarly reduced blood pressure and increased endothelium-dependent relaxations to acetylcholine (log shift at IC50, ie, half-maximal inhibition of a preceding contraction, 10-, 8-, 13-, and 13-fold, P < .05 versus control), whereas relaxations to the NO donor 3-morpholino sydnonimine (SIN-1, 10(-9) to 10(-5) mol/L) remained unaffected. In WKY, chronic therapy with nifedipine (10 mg.kg-1.d-1 PO) affected neither blood pressure nor relaxations to acetylcholine or SIN-1.
In rat coronary arteries, NO is synthesized via the endothelial L-arginine pathway and released after stimulation with acetylcholine. In SHR, chronic antihypertensive therapy with either angiotensin receptor antagonists, an angiotensin-converting enzyme inhibitor, or a calcium antagonist specifically increased the normal endothelium-dependent relaxations to acetylcholine, probably because of their blood pressure-lowering effects, whereas the responsiveness of vascular smooth muscle to NO remained unaffected.
Ni–YSZ cermets for SOFC anodes were prepared by the Pechini-type reaction route. The initial polymer precursors were prepared with different citric acid/ethylene glycol (CA/EG) molar ratios. The ...properties of the samples at different stages of the preparation procedure were evaluated with regard to thermal decomposition (TG–DTA), crystallite size (XRD), surface area (BET), sinterability and phase distribution (SEM). The results showed that an increase of CA and EG in the starting solution increased the final temperature of the thermal decomposition of gels from 340
°C to 382
°C, and the specific surface area of calcined NiO–YSZ powders from 10
m
2
g
−1 to 27
m
2
g
−1. In parallel the sinterability of the samples increased. A distinct increase of CA in the predominantly aqueous solution diminished the nickel grain size in the final Ni–YSZ material. A shift from aqueous to organic media further reduced the nickel-rich regions to around 0.2
μm.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The synchrophasor technology is maturing to large scale applications. Recent large scale deployment projects emphasize the importance of standards for accuracy and interoperability. Creation of large ...interconnected networks of Phase Measurement Units requires testing and calibration, as well as integration of embedded monitoring and control systems in the power networks. Such integration creates challenges, but also provides unprecedented opportunities for the flexible control and protection of large scale power systems.
Summary form only given. With the spotlight on smart grid development around the world, it is critical to recognize the key factors contributing to changing power system characteristics. This is more ...apparent in distribution systems with the integration of renewable energy sources, energy storage, and microgrid development. Source and load control at the distribution level is a key requirement of the evolving system. These activities require distribution automation (DA) strategies that take advantage of available technologies, while promoting newer solutions. It is necessary to create a roadmap for holistic DA strategies in a smarter grid. Sustainable and resilient grid development is a paradigm shift requiring a new line of thinking in the engineering, operation and maintenance of the power system. Distributed control architectures based on dynamic load and source data should be explored as a possible solution. This paper discusses a novel approach that integrates protection, control and monitoring using high-performance computing at the primary distribution substation level. The business case for infrastructure investment in the distribution systems is also discussed. The paper concludes with a discussion on emerging and future technologies for DA to improve the resiliency of a sustainable grid.
Conflicts between wildlife and humans have been reported from all over the world, but in Croatia the extent and intensity of the conflict is increasing. Agricultural damage by game is a major concern ...for both agricultural and wildlife agencies at the national level. In this study 4,695 cases of game damage over a 4-year period were analysed. Results indicated that the total amount of economic impact on agriculture from game damage was significant. The distribution of payments shows that a majority of payments have lower economic value with an average amount of single payment being 477.08 euro. The annual number of payments was found to have a negative correlation coefficient (-0.469) to the total payment amount for damages. According to the number of payments (68% of the number of payments) and the payment amount (60% of total payment amount), the crop most often damaged was maize. Analysis of the data found that there was a negative growth trend of payment frequency and total payment amount for grape vineyards. The correlation between yearly number of payments and yearly production was not calculated for any crop. The high seasonal nature of payments was a determent of seasonal regression using a dummy variable regression (r.sup.2=0.93). A comparison of the monthly number of payments and monthly amounts is depicted by a time series using a seasonal line. The impact of wild boar damage on agriculture crops, in total, leads to the conclusion that this game species is a major problem. The results showed a specific subset of game damage in Croatia and, as such, it can be extrapolated to provide insight into the damage caused by wild boar in other countries.
Due to environmental and demographic impacts, there is a high probability of a series of changes occurring on our planet over the next decades. In addition, a significant increase in the prices of ...all hydrocarbons due to limited world reserves is expected in the next decades. The combined use of renewable energy technologies and alternative energy technologies is a promising approach to reduce global warming effects in the world. In this paper, a solar concentrated power plant analysis based on the Rankine Cycle (RC) is performed, heated by means of various renewable energy sources. First, solar energy is used, followed by wood biomass energy. The solar energy is used during days full of sunshine. The heat energy from the concentrated solar power system process, stored in the big heat reservoir, is used to produce hydrogen during the night and during cloudy weather. In the period without sunshine and when we use all heat from the heat reservoir, biomass energy is used. This article examines the efficiency of a specific thermochemical hydrogen production cycle called the Copper-Chlorine cycle (CuCl). In the article, energy and economy analysis for the case of central European market prices, will be analyzed.
PDF
