Modular Wavemaker Design for Harbours and Ships Physical Model Testing

The paper presents design and implementation of a portable modular wavemaker system for producing regular and irregular waves in laboratory basins and fl umes. The system was built for the purpose of testing the impact of the sea waves on ships and coastal facilities. It is suitable for generation of all tipes regular and irregular surface waves. Modular system structure maintains high degree of fl exibility and reusability. Finally, the testing process on the physical model of Split harbour is described, and the currently obtained results are shown

Sulphur Compound Distributions in the Upper Jurassic Source Rocks from the Dinarides

The distribution of elemental sulphur and sulphur bound in inorganic and organic compounds was investigated for three surface samples of the oil-source rock from the Upper Jurassic strata in the Dinarides. Concentrations of elemental sulphur are very low and the concentrations of sulphur bound in pyrite and sulphates are relatively low. On the other hand, organically-bound sulphur in both kerogens and bitumens is rather high, representing almost a tenth of the bitumens and the kerogens by weight. Among the organo-sulphur compounds in bitumens, analyzed by GC-MS, alkylthiophenes, alkylbithiophenes, alkylthiolanes, alkylbenzothiophenes and alkyldibenzothiophenes were identified. Among the pyrolysis products of kerogens alkylthiophenes, alkenylthiophenes and benzothiophenes were identified. Based on similar sulphur distribution and the same organo-sulphur compounds identified in the bitumens and kerogen pyrolysates, samples are thought to be geochemically related. The extremely high concentrations of organic matter and of organically-bound sulphur indicate that the depositional environment of the Upper Jurassic strata in the Dinarides was most probably anoxic and iron lean

Isolation of Yttrium and Strontium from Soil Samples and Rapid Determination of 90Sr

A procedure of yttrium and strontium separation from calcium and other cations has been developed for rapid determination of 90Sr in soil samples. The procedure involves yttrium, strontium and other cations bound on cation exchanger AMBERLITE IR-120, separtion of yttrium and strontium from other cations, e.g. potassium, calcium, sodium, barium, on anion exchangers AMBERLITE CG-400 or DOWEX AG 1 × 8 with 0.25 mol l-1 HNO3 in alcohol mixture as eluent, separation of yttrium from strontium on cation exchanger DOWEX 50 × 8 with 3 mol l-1 HNO3, and determination of 90Sr on the low-level gas-flow β-counter and by Cherenkow counting on the liquid-scintillation counter. It has been shown that this procedure might be successfully applied in rapid determination of 90Sr, in a timesaving manner and without application of strong, concentrated acids. The method is appropriate for determination of the water soluble fraction of 90Sr in different kinds of environmental samples (milk, water, wine, vegetables, etc.) with some modification of the sample preparation procedure

Isolation of Yttrium and Strontium from Soil Samples and Rapid Determination of 90Sr

A procedure of yttrium and strontium separation from calcium and other cations has been developed for rapid determination of 90Sr in soil samples. The procedure involves yttrium, strontium and other cations bound on cation exchanger AMBERLITE IR-120, separtion of yttrium and strontium from other cations, e.g. potassium, calcium, sodium, barium, on anion exchangers AMBERLITE CG-400 or DOWEX AG 1 × 8 with 0.25 mol l-1 HNO3 in alcohol mixture as eluent, separation of yttrium from strontium on cation exchanger DOWEX 50 × 8 with 3 mol l-1 HNO3, and determination of 90Sr on the low-level gas-flow β-counter and by Cherenkow counting on the liquid-scintillation counter. It has been shown that this procedure might be successfully applied in rapid determination of 90Sr, in a timesaving manner and without application of strong, concentrated acids. The method is appropriate for determination of the water soluble fraction of 90Sr in different kinds of environmental samples (milk, water, wine, vegetables, etc.) with some modification of the sample preparation procedure

Modular Wavemaker Design for Harbours and Ships Physical Model Testing

The paper presents design and implementation of a portable modular wavemaker system for producing regular and irregular waves in laboratory basins and fl umes. The system was built for the purpose of testing the impact of the sea waves on ships and coastal facilities. It is suitable for generation of all tipes regular and irregular surface waves. Modular system structure maintains high degree of fl exibility and reusability. Finally, the testing process on the physical model of Split harbour is described, and the currently obtained results are shown

Zamjena dijela sustava turbinske regulacije na HE Čakovec

U radu je predstavljena zamjena dijela sustava turbinske regulacije proizvodnih jedinica A i B HE Čakovec. U uvodu su navedeni bitni razlozi za zamjenu dijela sustava turbinske regulacije. Nakon toga predstavljeni su podsustavi sustava turbinske regulacije: turbinski regulator, upravljanje nizvodnim zatvaračima, mjerenja razina vode i elektrohidraulički dio sustava turbinske regulacije. Također je predstavljeno mjerenje razina vode s hardverskom strukturom posebno prilagođenom za ova kontinuirana mjerenja. Posebna pozornost posvećena je dodatnoj funkciji turbinskog regulatora za nadzor kvarova u sustavima pozicioniranja privodnog i radnog kola. Dodatno su opisana HIL ispitivanja (Hardware in the Loop testing) sustava turbinske regulacije koja su provedena prilikom tvorničkih ispitivanja i navedene njihove prednosti. Opisan je registrator prijelaznih pojava i događaja. Na kraju je dan osvrt na primopredajna ispitivanja, te redoslijed projektiranja i izvođenja radova na HE Čakovec

Zamjena sustava turbinske regulacije proizvodne jedinice B HE Dubrovnik

U članku je predstavljena zamjena sustava turbinske regulacije proizvodne jedinice B HE Dubrovnik. U uvodu su navedeni glavni razlozi za zamjenu sustava turbinske regulacije. Nakon toga opisani su radovi i usluge potrebni za isporuku sustava po načelu ključ u ruke. Opisan je postupak projektiranja sustava. Predstavljeni su podsustavi sustava turbinske regulacije: elektrohidraulički podsustav sa hidrauličkim agregatom, hidrauličkim akumulatorima i hidrauličkim servomotorima, senzorika sustava turbinske regulacije, te ormari pomoćnih pogona i turbinske regulacije. Naznačeno je upravljanje sustavom turbinske regulacije. Navedena su tvornička, primopredajna ispitivanja i puštanje u pogon. Na kraju je dan osvrt na primopredajna ispitivanja i puštanje u pogon proizvodne jedinice B HE Dubrovnik