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The order of magnitude of increased growth, multiplication rate, and decreased sporulation of Bacillus subtilis after exposure to nanotesla magnetic fields (MFs) relative to control samples were observed experimentally. Earth’s total magnetic field intensity was reduced from 47.9 +– 0.4 mT to cover the range from 97.5 +– 1.7 nT to 1115 +– 158 nT in eight subsequent experiments by using three pairs of Helmholtz coils combined with Mu-metal shielding. The growth, multiplication rate, sporulation, and potassium content were measured in the probe and control containing B. subtilis cultures after 24 h of exposure to nanotesla and Earth’s magnetic fields, respectively. The observed effect is discussed with regard to its possible repercussions on Earth’s living species during geomagnetic reversals that occurred when the magnetic field was much weaker than the field that exists today. In addition, effects on future manned voyages into deep space, an environment with reduced magnetic field intensity, are considered.

Purpose: Measurement of carbon in cores of undisturbed sediments may provide valuable information on historical trends in sea primary production and carbonate precipitation which can be related to climate changes. Since core sediments are usually subjected to a different analysis, it is important to preserve the sample. Anon-destructive technique for carbon measurement in sedimentsbased on Fast Neutron Activation Analysis (FNAA) has been developed, which might replace the Loss-on-Ignition (LOI) as a conventional method for carbon analysis. Materials and methods: Method was tested on sediment samples collected from the Western Black Sea at depths up to 22 m. A surface sample and a corecut in centimeter intervals were freeze-dried. Samples weighing between 60 and 300 g were irradiated with the portable neutron generator. Gamma rays from 12C(n, n'γ)12C nuclear reaction were collected between 2000 and 4000 s by LaBr3:Ce detector. Standards for direct comparison and construction of the calibration line were prepared as mixtures of different amounts of quartz sand and graphite powder. FNAA results for total carbon (TC) were verified by LOIat 1000°C.LOIat 450°C and treatment with 1 M HCl were used to separate inorganic carbon (IC) and organic carbon(OC), respectively, followed by the FNAA measurements. Results and discussion: Climate effects on physical and biological marine processes are evident as historical changes in carbon flux to sediments. Carbon in sediments is found in the form of the OC produced byphotosynthetic organisms and as IC produced by calcifying organismsand precipitated as calcite. The FNAA is usually applied to samples weighing more than 1 kg. The method was optimized to reduce the minimum weight of the sample to 60 g, after subsequent adaptation of the set-up geometry.Carbon content measured in cores and surface sediment was between 2.8 and 6.1 wt%. OC constituted up to 84% of TC measured in the core.FNAA measurements were in good agreement with LOI analysis. Conclusions: The results have shown that FNAA can be used for the non-destructive determination of carbon in sediments in samples weighing ≥ 60g.FNAA is non-destructive, robust and fast in comparison to conventional methods for carbon determination such as LOI.The disadvantage is a relatively high MDL of 1%.

Prompt gamma-ray neutron activation analysis (PGNAA) has been widely used for elemental analysis of bulk samples as it provides an on-line, rapid and non-destructive means of performing such analysis. The Monte Carlo Library Least-Squares (MCLLS) approach is one of the methods for quantitative analysis providing elemental weight fractions via an assumption that the total prompt gamma-ray spectrum is a linear combination of the contributions from the individual prompt gamma-ray spectra of the sample constituents. For the generation of prompt gamma-ray libraries of each constituent, a specific purpose Monte Carlo code system called Center for Engineering Applications of Radioisotopes Coincidence Prompt Gamma-Ray (CEARCPG) is utilized. In this work, the focus was on detecting and measuring chlorine impurity in crude oil samples, i.e. trace amounts of chlorine. A preliminary study investigating the feasibility of PGNAA method in conjunction with the MCLLS approach for measuring trace amounts of chlorine in oil samples was performed. For this purpose, an extended version of the MCLLS approach, the so-called MCLLSX approach, was proposed and applied for the quantitative analysis. The results presented in this paper prove the feasibility of the proposed approach.

The order of magnitude of increased growth, multiplication rate, and decreased sporulation of

In this paper the properties of clay bricks with 5 wt%, 10 wt%, and 20 wt% sewage sludge ash (SSA) were studied and compared with the properties of control bricks made of 100% clay. Sewage sludge (SS) was collected at two wastewater treatment plants (WWTPs) in Croatia—WWTP Zagreb and WWTP Karlovac—and incinerated at a temperature of 900 °C The bricks were produced on a laboratory scale. A total of seven types of bricks were produced—control bricks and six types of bricks as combinations of different wt% of SSA generated from SS that was collected at two different WWTPs. The physical and mechanical properties of produced bricks were tested. Compressive strengths of bricks with 5 wt% SSA (54.0–54.5 N/mm2) and 10 wt% SSA (50.2–51.0 N/mm2) were higher compared to the control bricks (50.4 N/mm2), while bricks with 20 wt% SSA (37.0–43.9) N/mm2) had noticeably lower compressive strenght. The coefficient of saturation was lower for bricks with SSA compared to control bricks. The initial absorption values were more pronounced for SSA fractions of 20 wt%.

An important challenge in the petroleum industry is to reduce the salt content to acceptable levels in crude oil. Continuous monitoring of crude oil salinity is thus an important aspect. However, development of safe and reliable on-line and non-intrusive monitoring systems is still a challenging task. In this work, a method for non-intrusive, on-line monitoring of the chlorine impurity in crude oil based on prompt gamma-ray neutron activation analysis (PGNAA) in conjunction with a portable pulsed neutron generator producing 14 MeV neutrons in deuterium-tritium (DT) nuclear reactions is proposed and tested. Simulations with Monte Carlo N-Particle version 6 (MCNP6) transport code combined with Center for Engineering Applications of Radioisotopes Detector Response Function (CEARDRF) and a specific purpose Monte Carlo code called Center for Engineering Applications of Radioisotopes Coincidence Prompt Gamma-Ray (CEARCPG) were used for the design optimization of the experiments. Preliminary results indicate that a minimum detection limit for chlorine impurity of about 71 mg/L is achievable for an integration time of 30 min.

Svrha ovog rada bila je razviti sustav pročišćavanja podzemne vode koja se koristi za ljudsku potrošnju s visokim koncentracijama arsena i mangana te povišenim vrijednostima amonija i organskog opterećenja. U tu svrhu je korištena podzemna voda iz četiri bunara s područja Vukovarsko-srijemske županije (Andrijaševci, Antin, Komletinci i Vrbanja). Najviše vrijednosti arsena su izmjerene u Vrbanji (179 µg dm-3) a mangana u Antinu (154,5 µg dm-3). Zbog kompleksnog sastava podzemne vode sustav pročišćavanja je uključivao kombinirani pristup uključujući prethodno ozoniranje, glavnu elektrokemijsku obradu primjenom željezovih i aluminijevih elektroda bez/sa istovremenim ozoniranjem te završnu oksidaciju reaktivnim oksidativnim produktima nastalim istovremenom primjenom UV zračenja, ozona i ultrazvuka. Nakon kombiniranog postupka pročišćavanja svi mjereni pokazatelji u vodi iz sva četiri bunara su bili niži od MDK. Postignuto je potpuno uklanjanje arsena, boje, mutnoće, suspendirane tvari, organskih pokazatelja, nitrata, nitrita i fluorida te teških metala Hg, Co, Ni, Pb i Cd. Uklanjanje mangana se kretalo od 99,55 % do 99,99 % a amonija u rasponu od 99,5% do 99,7 %. Navedenim postupcima obrade dobivena je pitka voda sigurna za ljudsku potrošnju s kemijskog i toksikološkog stajališta., The purpose of the paper is the development of a treatment system for groundwater used for human consumption with high arsenic and manganese concentrations and increased values of ammonium and organic load. To this end, groundwater from four wells in the Vukovar – Srijem County (Andrijaševci, Antin, Komletinci and Vrbanja) was used. The highest arsenic value was measured in Vrbanja (179 µg dm-3) and the highest manganese value in Antin (154.5 µg dm-3). Due to a complex groundwater composition, the treatment system included a combined approach with prior ozonation, main electrochemical treatment using iron and aluminium electrodes with/out simultaneous ozonation and final oxidation using reactive oxidative products generated by simultaneous application of UV radiation, ozone and ultrasound. Following the combined treatment procedure, all measured indicators in water from all four wells were lower than the MAC. The complete removal of arsenic, colour, turbidity, suspended solids, organic indicators, nitrates, nitrites and fluorides as well as heavy metals (Hg, Co, Ni, Pb and Cd) was achieved. The removal of manganese ranged from 99.55 % to 99.99 % while the ammonium removal ranged from 99.5% to 99.7 %. These treatment procedures resulted in drinking water that is safe for human consumption from the chemical and toxicological viewpoints., Das Ziel dieser Arbeit war es, ein Konzept zu entwickeln zur Reinigung des Grundwassers, das für den menschlichen Gebrauch bestimmt ist, weist aber höhere Arsen- und Mangankonzentrationen, erhöhte Ammoniumwerte und organische Belastung auf. Vier Tiefbrunnen in der Gespanschaft Vukovar-Srijem – Andrijaševci, Antin, Komletinci und Vrbanja – sind in die Arbeit einbezogen worden. Die höchsten Arsenwerte wurden in Vrbanja (179 µg dm-3) und die höchsten Manganwerte in Antin (154,5 µg dm-3) gemessen. Wegen der komplexen Zusammensetzung des Grundwassers besteht das Reinigungssystem aus einer Kombination von Vorozonung, Hauptbehandlung, die aus dem elektrochemischen Verfahren unter Verwendung von Eisen- und Aluminiumelektroden mit oder ohne gleichzeitige Ozonung besteht, und Endozonung mit reaktiven Oxidationsprodukten, die bei gleichzeitiger Anwendung von UV-Bestrahlung, Ozon und Ultraschall entstanden. Nach diesem Kombinationsverfahren wurden die Werte aller Parameter im Wasser aus allen vier Brunnen niedriger als die höchstzulässigen Werte. Vollständige Entfernung von Arsen, Farbe, Trübung, Schwebstoffen, organischen Indikatoren, Nitraten, Nitriten, Fluoriden und Schwermetallen Hg, Co, Ni, Pb und Cd wurde erzielt. 99,55 % bis 99,99 % Mangan sowie 99,5% bis 99,7 % Ammonium wurde auch entfernt. Durch den Einsatz der angeführten Verfahren wird das Wasser vom chemischen und toxikologischen Standpunkt als Trinkwasser für den menschlichen Gebrauch geeignet sein.

The prospecting activities for finding new rare earth elements (REE) sources have increased greatly in recent years. One of the main discoveries was announced in 2011 by Japanese researchers who found large quantities of REE on the ocean seafloor at the sea depths greater than 4,000 m. The classic approach to investigate REE in deep sea sediments is to obtain sediment samples by drilling that is followed by laborious laboratory analysis. This is very expensive, time consuming and not appropriate for exploring vast areas. In order to efficiently explore the ocean floor for REE deposits, the further development of affordable sensors is needed. Here, we propose two nuclear techniques for exploring REE in surface deep sea sediments: i) Passive measurement of lutetium-176 radioactivity, appropriate if long-term in-situ measurements are possible, and ii) The use of the neutron sensor attached to a remotely operated vehicle for rapid in-situ measurement of gadolinium by thermal neutron-capture. Since concentrations of lutetium and gadolinium show strong linear correlation to the total REE concentrations in deep sea sediments, it is possible to deduce the total REE content by measuring Lu or Gd concentrations only.

U radu je praćena detoksifikacija otpadne vode od prerade grožđa kroz različite faze kemijske i elektrokemijske obrade. U cilju uklanjanja organskih/anorganskih onečišćivala iz otpadne vode korištena je oksidacija ozonom i taloženje pomoću CaO kao faza predobrade te tri elektrokemijske metode (elektrooksidacija, elektroredukcija i elektrokoagulacija) korištenjem elektroda od nehrđajućeg čelika, željeza i aluminija uz istovremeno ozoniranje u svrhu glavne obrade. Toksični učinak otpadne vode prije i nakon svake od faza pročišćavanja praćen je preko vrijednosti parametara klijavosti nakon izlaganja biljke Hordeum vulgare L. uzorcima nepročišćene/pročišćene otpadne vode. Otpadna voda je okarakterizirana niskom pH vrijednošću (4,02), intenzivnim mirisom i obojenjem (28400 PtCo), visokim vrijednostima organskih pokazatelja (18430 mg dm-3 KPK, 1340 mg dm-3 ukupnih fenola, 1720 mg dm-3 BPK5) te povišenim vrijednostima hranjivih soli i teških metala. Sinergijski i aditivni učinak između organskih pokazatelja, prvenstveno fenola i teških metala te niska pH vrijednost su vjerojatno odgovorni za izuzetno visok fitotoksični učinak s EC50 vrijednošću od svega 0,08 % te potpunim zastojem klijavosti nakon izlaganja sjemena nerazrijeđenoj otpadnoj vodi. Predobrada vapnom pri kojoj je uklonjeno između 46% i 99,8% teških metala, 90,4 % boje, 98,3 % mutnoće, 98,6 % UST, 95,4 % fosfata, 91,5 % sulfata te između 39 % i 47 % organskih pokazatelja je rezultirala 50 %-tnim smanjenjem toksičnog učinka. Završnom obradom dobiven je bistar efluent bez mirisa i s jedva primijetim obojenjem sa stupnjem uklanjanja karakterističnih pokazatelja između 73,8 % i 100 %, čime je u potpunosti uklonjen i njegov toksični učinak (Klijavost = 99,2±0,2 %; Indeks klijavosti = 99,2±0,2 %). Iz navedenog je moguće zaključiti da je odabrani set metoda pogodan za detoksifikaciju biološki slabo razgradljivih efluenata vrlo složenog i varijabilnog sastava kao što su vinarijske otpadne vode. Utvrđivanje parametara klijavosti na biljci Hordeum vulgare L. se pokazalo kao vrlo osjetljiv, jednostavan i jeftin test sustav za praćenje toksičnog učinka industrijskih efluenata te praćenje stupnja njihove detoksifikacije u toku različitih faza i metoda obrade., The paper monitors detoxification of wastewater from the processing of grapes through various phases of chemical and electrochemical treatment. For the purpose of removing organic / inorganic pollutants from wastewater, oxidation with ozone and sedimentation with CaO were used as preliminary treatment phases as well as three electrochemical methods (electro-oxidation, electro-reduction and electro-coagulation) utilizing electrodes made of stainless steel, iron an aluminium, with a simultaneous ozonation as the primary treatment. The toxic effect of wastewater before and after each treatment phase was monitored through the values of the germination parameter after exposure of the plant Hordeum vulgare L. to the samples of untreated/treated wastewater. The wastewater was characterized by low pH value (4.02), intense odour and colouring (28400 PtCo), high values of organic pollutants (18430 mg dm-3 COD, 1340 mg dm-3 total phenols, 1720 mg dm-3 BOD5) and elevated values of nutrients and heavy metals. The synergic and additive impact among organic indicators, primarily phenols and heavy metals and a low pH value, were probably responsible for an extremely high phytotoxic impact with the EC50 value of only 0.08 % and a full cessation of the germination after the seed exposure to undiluted wastewater. A preliminary treatment with lime, which removed 46% - 99.8% of heavy metals, 90.4 % of colour, 98,3 % of turbidity, 98.6 % total suspended solids, 95,4 % of phosphates, 91.5 % of sulphates and 39 % - 47 % of organic indicators, resulted in 50 % toxic impact reduction. The final treatment resulted in clear effluent without odour and a barely noticeable colouring, with a removal degree of characteristic indicators from 73.8 % to 100 %, which also fully removed its toxic impact (germination = 99.2±0.2 %; germination index = 99.2±0.2 %). Based on the above stated, it can be concluded that the selected set of methods is suitable for detoxification of biologically poorly degradable effluents of a very complex and variable composition, such as wastewater from the wine-making process. The determination of the germination parameters on the plant Hordeum vulgare L. proved to be a very sensitive, simple and inexpensive test system for monitoring the toxic impact of industrial effluents and the degree of their detoxification in different treatment phases and with different methods.

U radu je ispitana mogućnost primjene elektrokemijskih metoda (elektroredukcije, elektrokoagulacije, indirektne anodne oksidacije) korištenjem željezovog i aluminijevog seta elektroda sa ili bez dodatka elektrolita za obradu otpadne vode koja nastaje u procesu površinske zaštite metala. Otpadna voda je karakterizirana visokim vrijednostima cinka (2029 mg dm-3) i željeza (78,4 mg dm-3) te povišenim vrijednostima Cr(VI) (5,4 mg dm-3) i kemijske potrošnje kisika (820 mg dm-3) koje premašuju granične vrijednosti za ispust u okoliš za 1014, 39, 56, odnosno 6,6 puta. U svrhu optimizacije procesa u radu je ispitan utjecaj vrste elektroda (željezo, aluminij), kontaktnog vremena (5-30 minuta), mase elektrolita (0,5-1,5 g NaCl) te jakosti struje (20-50 A) na stupanj uklanjanja navedena četiri pokazatelja. Između dvije testirane elektrode, željezova se pokazala značajno efikasnijom u uklanjanju svih mjerenih pokazatelja, a naročito Cr(VI) i KPK. Statistički značajno bolji rezultati u uklanjanju KPK za obje elektrode su postignuti dodatkom elektrolita te porastom jakosti struje s 20 na 40 A. Najveći udio anorganskog onečišćenja se ukloni u prvih 5 minuta obrade. Najbolji rezultati su postignuti kombinacijom dviju elektroda uz dodatak klorida kao elektrolita. Nakon 15 minuta elektroredukcije/elektrokoagulacije/indirektne anodne oksidacije pomoću željezovih elektroda, 15 minuta elektrokoagulacije pomoću aluminijevih elektroda te 20 minuta koagulacije/flokulacije i oksidacije zrakom uklonjeno je 99,79% Cr(VI), 99,97% Fe, 98,23% Ni, 99,23% Cu, 99,999% Zn, 98,00% Pb i 86,46% KPK a svi mjereni pokazatelji su zadovoljavali uvjete za ispust u okoliš, dok su se izlazne koncentracije teških metala kretale od 0,009 do 0,023 mg dm-3., The paper investigated a possibility of implementing electrochemical methods (electroreduction, electrocoagulation, indirect anodic oxidation) by using iron and aluminium electrode sets, with or without the addition of electrolytes for treatment of wastewater generated in the process of surface protection of metals. The wastewater is characterized by high values of zinc (2029 mg dm-3) and iron (78.4 mg dm-3) as well as increased values of Cr(VI) (5.4 mg dm-3) and chemical oxygen demand (820 mg dm-3) that exceed limit values for discharge into the environment by 1014, 39, 56 and 6.6 times, respectively. In order to optimize the process, the paper investigated the impact of electrode type (iron, aluminium), contact time (5-30 minutes), electrolyte mass (0.5-1.5 g NaCl) and amperage (20-50 A) on the removal level of the stated four indicators. Of the two tested electrode types, iron electrodes proved to be significantly more efficient in the removal of all measured indicators, in particular Cr(VI) and COD. A statistically significant improvement of the results in COD removal for both electrode types was achieved by the addition of electrolytes and increased amperage from 20 to 40 A. The majority of inorganic pollution is removed in the first 5 minutes of treatment. The best results are achieved by a combination of the two electrode types, with the addition of chloride as an electrolyte. After 15 minutes of electroreduction / electrocoagulation / indirect anodic oxidation by iron electrodes, 15 minutes of electrocoagulation by aluminium electrodes and 20 minutes of coagulation / flocculation and oxidation by air, 99.79% Cr(VI), 99.97% Fe, 98.23% Ni, 99.23% Cu, 99.999% Zn, 98.00% Pb and 86.46% COD were removed. All measured indicators complied with the conditions for discharge into the environment whereas all output concentrations of heavy metals ranged from 0.009 to 0.023 mg dm-3.

U radu je prikazan postupak obrade kiselog efluenta nastalog u toku eksploatacije i prerade bakrene rude kompleksa Borskih rudnika (Bor- Krivelj-Cerovo) pomoću crvenog mulja - otpadnog produkta iz procesa proizvodnje glinice u bivšoj tvornici glinice iz Obrovca te primjena nastalog otpadnog mulja za pročišćavanje otpadnih voda iz prališta brodova. Izvršena je karakterizacija otpadnih voda i crvenog mulja te su utvrđeni optimalni uvjeti uklanjanja ključnih pokazatelja iz otpadnih voda. Rudnička otpadna voda je karakterizirana niskom pH vrijednošću (3,21), visokom koncentracijom sulfata (10830 mg dm-3), visokim vrijednostima željeza (921 mg dm-3), mangana (107 mg dm-3), bakra (92 mg dm-3) i cinka (59 mg dm-3), dok su u otpadnoj vodi iz prališta brodova ključna onečišćivala bakar (34 mg dm-3), cink (59 mg dm-3) i boja (11470 PtCo). Obzirom na visok neutralizacijski i sorpcijski kapacitet crvenog mulja, njegovo miješanje s rudničkom otpadnom vodom u optimalnim omjerima dovodi do neutralizacije oba otpadna produkta te uklanjanja teških metala iz otpadne vode ispod graničnih vrijednosti. Pri optimalnim uvjetima uklanjanja (pH = 8; kontaktno vrijeme = 15 minuta) uklonjeno je više od 99,9% Cr, Mn, Fe, Cu i Zn te 65,5% sulfata. Preostali otpadni mulj je moguće ponovo upotrijebiti za pročišćavanje otpadnih voda iz prališta brodova visoko opterećenih bojama protiv obraštaja, a s jednom dozom mulja je moguće izvršiti pet ciklusa pročišćavanja s učinkovitošću uklanjanja ključnih pokazatelja preko 99%., The paper presents a procedure for treating acidic effluent generated during the exploitation and proce¬ssing of copper ore at the Bor mining complex (Bor-Krivelj-Cerovo) by application of red mud, a waste by-product of the alumina production process at the now-defunct alumina plant in Obrovac, and the application of the generated waste mud to treating wastewater from ship cleaning facilities. The characterisation of wastewater and red mud was carried out, resulting in the determination of optimal conditions for the removal of key indicators from wastewater. The acidic mine wastewater is characterised by a low pH value (3.21), high sulfate concentration (10,830 mg dm-3), high values of iron (921 mg dm-3), manganese (107 mg dm-3), copper (92 mg dm-3) and zinc (59 mg dm-3), whereas the key polluters in the wastewater from ship cleaning facilities include copper (34 mg dm-3), zinc (59 mg dm-3) and paint (11470 PtCo). Considering a high neutralisation and adsorption capacity of red mud, its mixing with mine drainage wastewater in op¬timal ratios leads to the neutralisation of both waste by-products and the removal of heavy metals from wastewater to below their limit values. Under the optimal removal conditions (pH = 8; contact time = 15 minutes), more than 99.9% of Cr, Mn, Fe, Cu and Zn as well as 65.5% of sulfates were removed. The remaining waste mud can be reused in the treatment of wastewater from ship cleaning facilities which has a high load of anti-fouling paint. A single mud dosage is sufficient for five treatment cycles and has a key indicator removal efficiency rate of over 99%.

723 sediment samples collected along the eastern Adriatic coast have been analyzed using Energy Dispersive X-Ray Fluorescence. Factor Analysis and GIS have been used for the evaluation of the resulting data base containing information on K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Br, Rb, Sr, Y, and Pb concentration levels in order to find spatial relationships in distribution of measured elements. This study can be used to identify background values and to evaluate sediment quality standards.

A multi-sensor system was evaluated for the determination of barrel content with regard to eventual pollution hazards. The proposed system is able to investigate (in situ) the interior of a barrel filled with various unknown substances ranging from chemical and radioactive waste, raw sewage sludge, municipal incinerator ashes to common household trash. The crucial part of the system is a neutron sensor, which enables the identification of substance content without actually opening the barrel at all. A comparative laboratory test with the 3″×3″ and 5″×5″×10″ NaI(Tl) gamma ray detectors was made after which 3″×3″ detector was selected and incorporated in the submarine called “Surveyor”. A field test was made in the Croatian Adriatic coast on the island Losinj. Field tests show that the commercial system utilizing the described method could be constructed for barrel inspection regardless of the measurement environment (underwater, on land, dumping site, isolated location, etc.).

Boat Pressure Washing Wastewater Treatment with Calcium Oxide and/or Ferric ChlorideThe aim of this study was to investigate the efficiency of (1) chemical precipitation by calcium oxide, (2) coagulation/flocculation by ferric chloride (FC), and (3) the combination these two methods in reducing the toxicity of wastewater generated by boat pressure washing. All three methods gave satisfactory results in the removal of colour, turbidity, Cr, Fe, Cu, Zn, and Pb. The concentrations of heavy metals were lowered below national limits with 1 g of CaO, 2.54 mg of Fe3+ in the form of FeCl3x6H2O, and the combination of 0.25 g of CaO and 5.08 mg of Fe3+ per 50 mL of wastewater. Both CaO (1.50 g per 50 mL of wastewater) and FC proved efficient, but their combination yielded a significantly better performance: 99.41 %, 100.00 %, 97.87 %, 99.09 %, 99.90 %, 99.46 % and 98.33 % for colour, turbidity, Cr, Fe, Cu, Zn, and Pb respectively. For colour, Cr, Cu, Zn, and Pb removal efficiencies increased in the following order: FC

Chemical Profile of Plomin Bay SedimentsGranulometric, chemical, and leaching properties of sediments dredged in the Plomin Bay (Northern Adriatic Sea, Croatia) were investigated in order to asses the risk of remobilisation of heavy metals into the water column. In total 65 samples from 65 sampling sites were taken from different sediment depths within the bay. Analysis of variance confirmed the homogeneity of granulometric and elemental composition of the investigated sediment throughout its volume. Granulometric analysis showed that all samples corresponded to a pelitic fraction (-1 of V, 0.04 mg kg-1 of Cr, 0.07 mg kg-1 of Ni, 0.33 mg kg-1 of Cu, 0.67 mg kg-1 of Zn and 0.06 mg kg-1 of Pb could be remobilised from sediment material into the water column. However, these values increased three to ten times in case of leaching with organic acids.

U radu je prikazan novi kombinirani pristup u obradi otpadne vode koja nastaje u procesu prerade krumpira u čips kombinacijom elektrokemijskih metoda i ozoniranja. Otpadna voda je karakterizirana visokim vrijednostima ukupne suspendirane tvari (1517 mg dm-3), kemijske potrošnje kisika (2240 mg dm-3) te biokemijske potrošnje kisika (1780 mg dm-3) koje premašuju granične vrijednosti za ispust u okoliš za 43, 18 odnosno 71 puta. U svrhu optimizacije procesa u radu je ispitan utjecaj vrste elektroda (nehrđajući čelik, željezo, aluminij), kontaktnog vremena (5-30 minuta) te jakosti struje (30-100 A) na stupanj uklanjanja navedena tri parametra. Iako se aluminijev set elektroda pokazao najefikasnijim za uklanjanje navedenih pokazatelja, značajno bolji rezultati su dobiveni kombinacijom sve tri vrste elektroda uz istovremeno ozoniranje. Nakon 10 minuta elektrokoagulacije/elektroksidacije pomoću elektroda od nehrđajućeg čelika, 5 minuta elektrokoagulacije/ozoniranja pomoću željezovih elektroda, 15 elektrokoagulacije/ozoniranja pomoću aluminijevih elektroda te 15 minuta ozoniranja uklonjeno je 100% boje, mutnoće i UST, 94,5% KPK te 98,9% BPK5 a svi mjereni pokazatelji su zadovoljavali uvjete za ispust u okoliš., The paper presents a new approach which combines electrochemical methods and ozonation to wastewater treatment from potato processing in potato chips production. This wastewater is characterized by high values of total suspended solids (1517 mg dm-3), chemical oxygen demand (2240 mg dm-3) and biochemical oxygen demand (1780 mg dm-3) that exceed the limit values for discharges into the environment by 43.18 and 71 times, respectively. For the purpose of optimisation of this process, the paper investigated the impact of different electrode types (stainless steel, iron, aluminium), contact time (5-30 minutes) and amperage (30-100 A) on the degree of removal of these three parameters. Although the aluminium electrode set proved the most effective for the removal of these indicators, significantly better results were obtained by a combination of all three electrode types with simultaneous ozonation. After 10 minutes of electrocoagulation / electrooxidation with stainless steel electrodes, 5 minutes of electrocoagulation / ozonation with iron electrodes, 15 minutes of electrocoagulation / ozonation with aluminium electrodes and 15 minutes of ozonation, 100% colour, turbidity and TSS, 94.5% COD and 98. 9% BOD5 were removed, and all measured indicators met the requirements for discharges into the environment.

The possibility of the detection of “dirty bomb” presence inside sea containers is evaluated. The method proposed for explosive and fissile material detection makes use of two sensors (X-rays and neutrons). A commercial imaging device based on the X-ray radiography performs a fast scan of the container, identifies a “suspect” region and provides its coordinates to the neutron based device for the final “confirmatory” inspection. In this two sensor system a 14 MeV neutron beam defined by the detection of associated alpha particles is used for interrogation of only volume elements marked by X-ray sensor. The object’s nature is determined from passive and neutron induced, gamma energy spectra measurements. Experimental results (time-of-flight and gamma energy spectra) obtained for the irradiation 30 kg of TNT, depleted uranium and other materials hidden inside the container are presented.

Non-destructive inspection of luggage has been simulated in laboratory conditions by using a 14 MeV tagged neutron beam and BaF 2 scintillation detectors (Tagged Neutron Inspection System, TNIS). The tagged neutron beam is produced by detecting the associated alpha particle emitted in the D+T reaction by means of a YAP:Ce scintillator. The TNIS intrinsic time resolution has been measured to be δ t =0.9 ns [FWHM], which allows inspection of a minimum voxel of 5 cm depth along the neutron flight path. This characteristic is demonstrated by identifying graphite and water samples hidden inside a hard plastic suitcase filled with background material. Finally, explosive devices such as small anti-personnel or anti-tank landmines have been inspected when placed inside the suitcase. In the case of relatively large explosive objects such as an anti-tank landmine, the system is capable of testing directly the TNT charge inside the device, separating this material from the external plastic case. Further developments of the TNIS concept are discussed.

The detection of landmines by using available technologies is a time consuming, expensive and extremely dangerous job, so that there is a need for a technological breakthrough in this field. Atomic and nuclear physics based sensors might offer new possibilities in de-mining. Among the available nuclear techniques, the neutron backscattering technique (NBT), based on the detection of the produced thermal neutrons, is thought to be the most promising for field applications. We discuss here two limitations of NBT, being related to the soil moisture. First, the critical value of the soil moisture, reached when the density of the hydrogen atoms in the landmine is equal to that in the background soil, defines a condition for which the detection is not possible. Critical values are small for some of the landmine types, thus suggesting the application of the method to arid countries, where the soil moisture is lower than 10%. Furthermore, small-scale variations of the soil moisture content, experimentally determined for different soil types, are found to be capable of generating false positive readings. To avoid this problem, the integration of the NBT with a second sensor, as the metal detector, is proposed.

The aim of this study was to investigate the effi ciency of (1) chemical precipitation by calcium oxide, (2) coagulation/flocculation by ferric chloride (FC), and (3) the combination these two methods in reducing the toxicity of wastewater generated by boat pressure washing. All three methods gave satisfactory results in the removal of colour, turbidity, Cr, Fe, Cu, Zn, and Pb. The concentrations of heavy metals were lowered below national limits with 1 g of CaO, 2.54 mg of Fe3+ in the form of FeCl3×6H2O, and the combination of 0.25 g of CaO and 5.08 mg of Fe3+ per 50 mL of wastewater. Both CaO (1.50 g per 50 mL of wastewater) and FC proved efficient, but their combination yielded a significantly better performance: 99.41 %, 100.00 %, 97.87 %, 99.09 %, 99.90 %, 99.46 % and 98.33 % for colour, turbidity, Cr, Fe, Cu, Zn, and Pb respectively. For colour, Cr, Cu, Zn, and Pb removal efficiencies increased in the following order: FC, Radi smanjenja toksičnosti otpadnih voda koje nastaju pranjem brodova premazanih bojama protiv obraštaja primijenjene su tri metode obrade: (1) kemijsko taloženje s pomoću kalcijeva oksida, koagulacija/flokulacija s pomoću željezova klorida (FC) i (3) kombinacija ovih dviju metoda. Sve tri metode dale su zadovoljavajuće rezultate u uklanjanju boje, mutnoće, kroma, željeza, bakra, cinka i olova. Koncentracije teških metala niže od graničnih vrijednosti postignute su nakon tretmana s 1 g CaO ili 2,54 mg Fe3+ dodanog u obliku FeCl3×6H2O ili kombinacijom od 0,25 g CaO i 5,08 mg Fe3+ na 50 mL otpadne vode. Optimalne vrijednosti uklanjanja boje, mutnoće, Cr, Fe, Cu, Zn odnosno Pb s pomoću CaO (1,50 g na 50 mL) bile su 99,07 %, 99,54 %, 86,97 %, 96,77 %, 97,81 %, 98,76 % odnosno 84,10 %, dok su u slučaju željezova klorida te vrijednosti iznosile 98,76 %, 99,85 %, 78,99 %, 97,35 %, 96,77 %, 98,53 % odnosno 78,99 %. Značajno viši stupanj uklanjanja postignut je kombinacijom navedenih dvaju pristupa čime je postignuta maksimalna učinkovitost uklanjanja i to 99,41 % boje, 100,00 % mutnoće, 97,87 % kroma, 99,09 % željeza, 99,90 % bakra, 99,46 % cinka i 98,33 % olova. Za boju, krom, bakar, cink i olovo učinkovitost uklanjanja raste ovim redoslijedom: FC

Eksperimenti Ives-Stilwellovog tipa (IS) spadaju u klasu bazičnih eksperimenata za kinematičku provjeru Lorentzovih transformacija (LT), a usmjereni su na provjeru efekata dilatacije vremena. U skladu s pojmom prostorvremena Minkowskog fizikalne velicine su reprezentirane geometrijskim objektima 4D prostorvremena, a LT djeluje na kompletnu geometrijsku veličinu (u ovom slučaju valni četverovektor), a ne samo na njenu vremensku komponentu. Sva dosadašnja IS mjerenja relativističkog Dopplerovog efekta su vršena na nasuprotnim kutevima od 0 i 180 stupnjeva na kojima se relativistička aberacija ne pojavljuje. Takva mjerenja su nekompletna, jer se prostorne komponente valnog četverovektora zanemaruju. Zbog toga relativistički efekti nisu u eksperimentalnom smislu u cijelosti istraženi. Neka mjerenja na nasuprotnim kutevima različitim od 0 i 180 stupnjeva nisu pokazala relativističku asimetriju u Dopplerovom pomaku. Cilj ovog eksperimenta je razjasniti tu diskrepanciju mjerenjima na nasuprotnim kutevima različitim od 0 i 180 stupnjeva sa i bez korekcije za kut aberacije. Na korigiranim kutevima se očekuje opažanje relativističke asimetrije, čime bi se eksperimentalno potvrdilo da su relativistički Dopplerov efekt i aberacija manifestacije jedinstvenog fizikalnog procesa: Lorentzove transformacije potpune geometrijske veličine - valnog četverovektora iz jednog Lorentzovog sustava u drugi. U općem slučaju (npr. nestandardna sinhronizacija) te efekte nije moguće razdvojiti, odnosno nije ih moguće smatrati fizikalno dobro definiranima u 4D prostorvremenu. Kao gibajući izvor svjetlosti u našem eksperimentu služe pobuđeni neutralni vodikovi atomi dobiveni sudarima H2+ i H3+ iona ubrzanih u CW akceleratoru s molekularnim vodikom u niskotlačnoj, plinskoj vodikovoj meti, s dvostupanjskim sistemom za diferencijalno pumpanje. Emitirana svjetlost se analizira optičkim spektrometrom s dvije sonde, koje se pomoću goniometra postavljaju na nasuprotne kuteve korigirane za relativističku aberaciju. Iznos kuteva aberacije u intervalu energija od 150-275 keV je između 0.71 i 0.96 stupnjeva. Preliminarna spektroskopska mjerenja rađena su spektrometrom Avaspec-3648 Fiber Optics Spectrometer efektivnog spektralnog razlučivanja 0.6 nm. Mjereni su emisijski spektri pobuđenih vodikovih atoma transverzalno na smjer gibanja i pod kutem od 45 stupnjeva s obzirom na smjer gibanja vodikovih atoma. Ustanovljeno je da su dobro vidljive Balmerove H-alfa, H-beta, i H-gama emisione linije, kao i pomak spektralnih linija zbog Dopplerovog efekta.

Granulometric, chemical, and leaching properties of sediments dredged in the Plomin Bay (Northern Adriatic Sea, Croatia) were investigated in order to asses the risk of remobilisation of heavy metals into the water column. In total 65 samples from 65 sampling sites were taken from different sediment depths within the bay. Analysis of variance confirmed the homogeneity of granulometric and elemental composition of the investigated sediment throughout its volume. Granulometric analysis showed that all samples corresponded to a pelitic fraction (, Granulometrijska i kemijska svojstva te mogućnost otpuštanja teških metala ispitivani su u sedimentima Plominskog zaljeva (Sjeverni Jadran, Hrvatska) u svrhu utvrđivanja rizika od remobilizacije teških metala iz sedimenta u stupac vode. Uzeto je 65 uzoraka s različitih točaka i dubina unutar zaljeva. Analizom varijance potvrđena je granulometrijska i kemijska homogenost cijelog volumena sedimenta, što upućuje na jedan prevladavajući izvor tijekom cijeloga sedimentacijskog razdoblja. Granulometrijskom analizom je utvrđeno da u svim uzorcima prevladava sitnozrnata frakcija (

Kombiniranjem arhitekture sa slike 7 s principom racunala upravljanog tokom podataka (data flow) (u literaturi je takva arhitektura poznata kao 'wavefront processor' ili polja valne fronte), dobivaju se dodatna poboljsanja i u smislu povecanja brzine i u smislu jednostavnosti oblikovanja racunarskog sustava. Osim onih prednosti koje imaju sistolicka polja [5] i vec istaknutih svojstava, arhitektura sa slike 7 ima jos nekoliko dodatnih prednosti koja je cine izuzetno atraktivnom za adaptaciju DU radarske antene. To su: PE ne zahtijevaju memoriju; brzina triangulacije matrice, velicine nxn, iznosi 2(n-l) perioda signala vremenskog vođenja sistolickog polja; ukupan broj operacija je proporcionalan i dalje sa n3, ali je distribuiran na broj procesorskih elemenata koji je proporcionalan sa n2 (tacan broj PE dat je kao n(n+1)/2) i na broj signala vremenskog vođenja koji je proporcionalan sa n; algoritam GROT stabilniji je od algoritma SMI, uz ostalo i zato sto radi na matrici podataka koja prezentira 'napon' i upravo zbog toga dinamika broja je manja od broja potrebnog za SMI gdje matrica kovarijacije M predstavlja 'snagu'. Na opisani nacin može se napraviti vrlo efikasan racunski sustav za adaptaciju DU radarske antene. Međutim, imperativ njegova rada u 'radarskom' realnom vremenu namece zahtjeve za primjenu vrlo brzih tehnologija. Na primjer, za adaptaciju DU od sest kanala, s frekvencijom uzorkovanja radarskih signala od 10 MHz, potrebna propusna moc racunala je preko 3 GFLOPS-a (GFLOPS-milijarda operacija s pomicnim zarezom).

Non-destructive inspections have been simulated in laboratory conditions by using our tagged neutron inspection system (TNIS), using YAP:Ce scintillators to tag the neutron beam and an array of BaF2 crystals to detect the γ-rays. The system has been operated up to 2 × 108 neutron/s. Further developments of the TNIS concept are discussed in the light of our current projects for cargo container inspections.

The paper reviews the data of 10 yr of following up sewage (waste water) inflows of anthropological origin into the sea from all the coastal settlements in Croatia. In particular, we report the sea loading by biochemical oxygen demand (BOD5), expressed by the inhabitant equivalent (I.E.), for seven littoral counties. We estimated the loading of a coastal sea area for each county separately. The objective was to avoid any over- or underestimation of amounts and significance of sewage inflows into the seawater. For this purpose, a precisely determined sea volume up to the 10 m isobath has been chosen. Because of the inadequate treatment of wastewater, the total loading of that maritime territory expressed in terms of i.e. was found to be 26% higher than expected from the actual number of inhabitants. However, daily input represents only 12‰ of the considered volume of the sea. Recipient spent only 0.7% of the disposable oxygen quantity in the sea.

Long‐term observations of soil water content as well as determination of physical and chemical properties of different types of soils in Croatia were made in order to provide the necessary background information for landmine explosive detection. Soil water content is the key attribute of soil as a background in neutron backscattering technique (NBT) landmine detection application. If the critical value of the soil water content is reached, the detection of landmine explosives is not possible. It is recommended that soil moisture content for NBT application does not exceed 0.1 kg.kg−1 [1]. Nineteen representative samples of different soil types from different parts of Croatia were collected in order to establish soil bank with the necessary physical and chemical properties determined for each type of soil. In addition soil water content was measured on daily and weekly basis on several locations in Croatia. This procedure also included daily soil moisture measurements in the test field made of different types of soils from several locations in Croatia. This was done in order to evaluate the behavior of different types of soils under the same weather conditions.

In today's society acts of terrorism must involve in some stages the illicit trafficking either of explosives, narcotics, chemical weapons, hazardous chemicals, radioactive materials and/or humans. Therefore the society must rely on the modern anti-trafficking infrastructure including adequate instrumental base. Old control measures slow down the traffic flow, they are time consuming and inefficient. Recently lots of efforts has be put into development of the concept of "the smart border", border management system that keeps pace with expanding trade while protecting from the threats of terrorist attack, illegal immigration, illegal drugs, and other contraband. Due to the size of container transport industry the shipping container control system must be an essential building block of the smart border concept. The world's total movement in containers is estimated to be 72m TEU ("20-foot equivalent units"). A single typical large container ship can carry up to 6, 000 TEU. Although the container has become indispensable to world commerce, it also turned out to be handy ways to smuggle drugs, contraband and illegal immigrants. Modern cargo inspection systems are non-invasive imaging techniques, the inspection systems using penetrating radiations (1.33 MeV gamma and 0.3 and 0.45 MeV x-rays) in the scanning geometry. Relative penetration of the commonly used radiation is 17.5, 10.0 and 4.43 cm-iron for 1.33, 0.45 and 0.3 MeV, respectively. The concept of the multisensor system is based on the integrated use of gamma or x-ray fast scanning of the interrogated object (i.e. the whole container) with subsequent detailed elemental analysis of suspicious volumes by using fast neutrons. The use of alpha particle tagged neutron beams is a unique feature of such device in that it can enhance by a large factor the signal/noise ratio of the system. In the work reported here the neutron beam was obtained by means of D+T reaction. The associated alpha particle detector was fixed in such a way that the associated neutron beam was in horizontal plane at 90º ; ; ; to the deutron beam. Slit in front of the scintlillator was used to define the geometrical dimensions of the beam on the interrogated object. The α -γ coincidence spectra were measured with the selection of α -γ coincidences performed by the 100 ns TAC range. The information on the position of the interrogated object was contained in the TAC spectrum, while object's composition gave rise to characteristic gamma ray spectrum. In addition, conceptual design of the system, and preliminary data, for the inspection of the shipping containers for radioactive materials in the small to medium size container ports are reported. The aim was to detect the presence of shielded or unshielded sources inside the shipping container. This could be accomplished during the movement of the container: (i) from the ship to the storage area by radiation detector mounted on the crane and (ii) from the storage area while leaving the container port by track or train by gate monitors or by using gamma inspection systems in the passive mode.