Radioactive Contamination of the Soil: Assessments of Pollutants Mobility with Implication to Remediation Strategies

Accidental releases, nuclear weapons testing, and inadequate practices of radioactive waste disposal are the principal human activities responsible for radioactive contamination as a new and global form of soil degradation. Understanding the radionuclide distribution, mobility and bioavailability, as well as the changes caused by the variation of environmental conditions, is essential for soil rehabilitation. This chapter aims to highlight the importance of evaluating radionuclide distribution, for the selection of proper in situ or ex situ remediation strategy. Attention was focused onto remediation methods based on radioactive pollutants redistribution, for enhanced separation (chemical extraction) or containment (in situ immobilization). When the excavation and off-site leaching treatments are uneconomic, impractical, or unnecessary, in situ stabilization by the addition of appropriate reactive materials is an alternative approach. The optimization of factors in control of chemical leaching methods, selection of cost-effective immobilization agents, especially among suitable wastes and by-products, and verification of long-term effects of remediating actions are the major challenges for future investigation in this field. Furthermore, the improvement and standardization of the methods for radionuclide speciation are necessary to enable comparison between studies and monitoring of the effects achieved by the soil treatments

Evaluation of the impact of univeristy libraries in Croatia : a study of the impact of collections and services of university libraries on student academic achievement

U ovom radu istražuje se i analizira utjecaj zbirki i usluga sveučilišnih knjižnica na akademski uspjeh studenata na odabranim hrvatskim sveučilištima. U Hrvatskoj se do sada nisu provodila istraživanja utjecaja sveučilišnih knjižnica na korisnike, a istraživanja vezanih uz utjecaj knjižnice na obrazovanje studenata jako je malo i u svijetu. Razlog tome je činjenica da je takav utjecaj relativno teško izmjeriti, iako se radi o veoma važnim pokazateljima uspješnosti poslovanja određene knjižnice. U uvodnome dijelu upućuje se na značajne teorijske radove o važnosti vrednovanja, utjecaja knjižnica i knjižnične statistike, a u istraživačkom dijelu rada prikazani su i komentirani rezultati istraživanja utjecaja sveučilišnih knjižnica u Puli, Rijeci, Splitu i Zadru na akademski uspjeh studenata u navedenim gradovima.The paper studies and analyzes the impact of university library collections and services on student achievement at selected Croatian universities. There have not been any studies on the impact of university libraries on their users in Croatia until now, and such studies are rare even around the world. The reason for this probably lies in the fact that it is very difficult to determine this impact, although it is a very important indicator of library services efficiency. In the first part of the paper we present some relevant theoretical works on the importance of library evaluation, library statistics, and impact of libraries on their users. In the second part, we present and critically evaluate the results obtained in the study of university library impact on students’ achievement at Universities of Pula, Rijeka, Split, and Zadar

Ishodi glasovne terapije nakon lobektomije i totalne tireoidektomije

Voice disorders are among the most common complications of thyroid surgery. It is therefore advisable to continuously monitor and report the outcomes of voice rehabilitation among people who underwent thyroid surgery in order to recognize which specific clinical actions are necessary to give those patients the maximum chance to restore quality of life. The aim of this study was to examine the outcomes of voice therapy in 35 persons (26 women and 9 men) aged between 20 and 75 years after total thyroidectomy or lobectomy. Multidimensional voice assessment using the GRBAS scale, Voice Handicap Index questionnaire, and acoustic analysis was carried out before and after voice therapy, which included relaxation and breathing exercises, laryngeal massage, resonance therapy, and the employment of the digital compression method. Since the Wilcoxon Signed Ranks Test showed significant improvements in all voice parameters after voice therapy, voice rehabilitation seems to be the essential clinical activity for thyroid surgery patients who suffer from voice disorders postoperatively.Poremećaji glasa su među najčešćim posljedicama operacije štitne žlijezde. Stoga je preporučljivo kontinuirano izvještavati o rezultatima rehabilitacije glasa kod ljudi koji su prošli operaciju štitnjače, kako bi se prepoznalo koje su specifične kliničke radnje potrebne da bi se tim pacijentima pružila maksimalna šansa za vraćanje prijašnje kvalitete života. Cilj ovog istraživanja bio je ispitati rezultate glasovne terapije 35 osoba (26 žena i 9 muškaraca) u dobi između 20 i 75 godina, nakon lobektomije ili totalne tireoidektomije štitne žlijezde. Multidimenzionalna procjena glasa putem GRBAS ljestvice, upitnika Indeks vokalnih teškoća i akustičke analize provedena je prije i nakon terapije glasa, koja je uključivala vježbe opuštanja i disanja, masažu larinksa, rezonantnu terapiju i primjenu metode digitalne kompresije. Budući da je primjena Wilcoxonovog testa pokazala značajna poboljšanja u mjerenim parametrima nakon terapije glasa, čini se da je rehabilitacija glasa ključna klinička aktivnost za pacijente s operacijom štitne žlijezde kod kojih je postoperativno dijagnosticiran poremećaj glasa

Supplementary material for the article: Jevtić, I. I.; Došen-Mićović, L. I.; Ivanović, E. R.; Todorović, N. M.; Ivanović, M. D. Synthesis of Orthogonally Protected (±)-3-Amino-4-Anilidopiperidines and (±)-3- N -Carbomethoxyfentanyl. Synthesis (Germany) 2017, 49 (14), 3126–3136. https://doi.org/10.1055/s-0036-1588985

Supporting information for: [https://doi.org/10.1055/s-0036-1588985]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2492

Experimental and numerical analysis of thermo-chemical erosion in gun steel

Various factors of thermo-chemical erosion process in gun steel were analysed. The factors are mainly related to the thermal load of gun barrel inside surface, characteristics of barrel surface and chemical interactions between propellant combustion products and barrel surface. The experimental simulation of conditions in gun barrel was carried out by vented vessel firings in the device based on modification of 37 mm M39 gun. The nozzle mass loss during firing was the measure of gun steel erosion. The main thermal factor of erosion is maximum nozzle inner surface temperature. This temperature was determined experimentally by micro thermocouples measurements at specified distance away from the inner surface and by numerical analysis of the inverse heat conduction problem. Modelling of two-phase flow of propellant combustion products and unburned propellant grains in the vented vessel and heat transfer to the nozzle were conducted using developed 1-D interior ballistic code and CFD simulation in FLUENT. Influence of different propellants, TiO2/wax wear reducing liner and tungsten-disulfide nanoparticles layer on nozzle erosion was analysed. Good agreement between experimental and computational results was achieved

Influence of bentonite and zeolite on Cs+ and Co2+ cement matrix leaching phenomena

The probability of Cs+ and Co2+ ions retention by immobilization processes in the cement matrix was determinate as the subject of analyses: matrix design, water/cement ratio, and structure porosity. Comparison of experimental results was accomplished by Hespe standard leaching method. Diffusion and semi-empirical models were used for the assessment of the washing rate as a function of time. The higher value of cement matrix mechanical resistance corresponds to a lower value of Co2+ and Cs+ ions leaching. The Co2+ leaching level was more than two orders of magnitude less than the leaching level of Cs+. The influence of bentonite and zeolite on Co2+ leaching reduction was significantly smaller in comparison with Cs+, while zeolite had a higher Cs+ and Co2+ sorption ability than bentonite. Under static leaching conditions, the contribution of diffusion to the total transport of ions in the matrix porous medium was dominant. The contribution of matrix dissolution was insignificant concerning the dominant contribution of diffusion and surface washing. The semi-empirical model showed a better approximation of the Co2+ and Cs+ ions laboratory leaching process

Possibility of Reducing the Overpressure of Shock Wave of Powder Gases around the Mortar

This paper resulted from the research of the overpressure of the shock wave of the powder gases, which occurs during firing of the mortar. Work encompasses modeling and computation of the overpressure field. Increasing overpressure around the mortar is analyzed in the case of using the largest powder charges. In order to reduce the overpressure a corresponding technical solution has been proposed. The solution in the form of divergent nozzle has been proposed and it is placed at the barrel muzzle. The paper also analyzes the impact of this solution to reduce the overpressure intensity at the crew position.Computation results of the overpressure of the powder gases, which were obtained by the realization of numerical calculation, based on the application of the finite volume method, were confirmed by the experimental results, achieved in the firing experiments

Experimental and numerical analysis of thermo-chemical erosion in gun steel

Various factors of thermo-chemical erosion process in gun steel were analysed. The factors are mainly related to the thermal load of gun barrel inside surface, characteristics of barrel surface and chemical interactions between propellant combustion products and barrel surface. The experimental simulation of conditions in gun barrel was carried out by vented vessel firings in the device based on modification of 37 mm M39 gun. The nozzle mass loss during firing was the measure of gun steel erosion. The main thermal factor of erosion is maximum nozzle inner surface temperature. This temperature was determined experimentally by micro thermocouples measurements at specified distance away from the inner surface and by numerical analysis of the inverse heat conduction problem. Modelling of two-phase flow of propellant combustion products and unburned propellant grains in the vented vessel and heat transfer to the nozzle were conducted using developed 1-D interior ballistic code and CFD simulation in FLUENT. Influence of different propellants, TiO2/wax wear reducing liner and tungsten-disulfide nanoparticles layer on nozzle erosion was analysed. Good agreement between experimental and computational results was achieved

Pouzdanost kriminalističko-tehničkih metoda za detektovanje tragova barutnih čestica na šakama osumnjičenih

One of the most important facts in crimes involving firearms, crucial for their elucidation, is the identification of persons who had fired the shot during the critical incident. Gunshot residue on the skin of a suspect is important evidence for reconstructive questions in the forensic investigation of cases involving firearms. The subject of this paper is to analyze the gunshot residue - products of bullet firing from a hand gun in order to determine whether a person is actually shot in this case or not. Specifically, the paper will give a critical analysis of the methods of forensic practice in the region when it comes to expert trace analysis of the use of firearms and gunshot residue in particular, as well as recommendations for future research in GSR.Kod krivičnih dela izvršenih vatrenim oružjem jedna od veoma bitnih, a često i najvažnijih činjenica za njihovo rasvetljavanje je identifikacija lica koje je pucalo iz vatrenog oružja kritičnom prilikom. Tragovi barutnih čestica na koži osumnjičenog mogu biti važan materijalni dokaz u krivičnim delima sa upotrebom vatrenog oružja. Predmet ovog rada je analiza produkata opaljenja metka iz ručnog vatrenog oružja u cilju određivanja da li je neko lice zaista i pucalo u konkretnom slučaju. Naime, u radu će biti data kritička analiza pojedinih metoda kriminalističko-tehničke prakse zemalja u regionu kada je u pitanju veštačenje tragova upotrebe vatrenog oružja, konkretno barutnih čestica, kao i preporuka za buduća ispitivanja tragova barutnih čestica

The initial analysis of the river Ibar temperature downstream of the lake Gazivode

As a result of a very limited number of geometric and other input data, the temperature modeling of the river Ibar downstream of the lake Gazivode was started by analyzing one river reach between Pridvorica, secondary dam in the system Gazivode, and the city Kosovska Mitrovica. River reach was selected so that the numerical results can be compared with available measured temperature data. Water quality component of HEC-RAS one-dimensional hydraulic river model was used for temperature calculations