M. Pavlun — doctor of geological sciences, professor, dean the faculty Ivan Franko National University Lviv, academician Academy Sciences Higher School Ukraine, full member Ukrainian Mineralogical Society, Shevchenko Scientific Society. Pavlun’s systematic scientific research on metallogeny and thermobarogeochemistry (TBGC) molybdenum-tungsten gold ore formations served as basis for preparation...

An Order-Revealing Encryption (ORE) scheme gives a public procedure by which two ciphertext can be compared to reveal the order of their underlying plaintexts. The ideal security notion for ORE is that only the order is revealed — anything else, such as the distance between plaintexts, is hidden. The only known constructions of ORE achieving such ideal security are based on cryptographic multil...

Nome placer offshore gold grade estimation is a challenging problem in light of extreme ore heterogeneity. However, this type of phenomenon is quite common in placer ore grade variation. Further, the characterization of spatial ore grade variability and subsequent ore grade modelling of the deposit becomes problematic due to the unavailability of adequate samples. Being located in the Arctic, t...

The present research paper deals with the oxidation process of molybdenum ore. The main target of the present study is the up-gradation of MoO3 from roasted molybdenum ore by a leaching process without waste generation. The most important application of hydrometallurgical processing is the leaching process of the ore and it is the primary process to make pure metal from ore. The present investi...

A typical South Crofty ore containing minor amounts of arsenopyrite and chalcopyrite (ore A) gives 65% overall recovery of cassiterite in the spiral circuit, overall enrichment ratios being about 25-35. Maximum recovery occurs in the size range 53-110 /Lm(Fig. 2). However, recently treated ore types (ore B) have been much richer in sulphides, yielding up to 30°" As in the recleaner table concen...

A double Ore extension is a natural generalization of the Ore extension. We prove that a connected graded double Ore extension of an ArtinSchelter regular algebra is Artin-Schelter regular. Some other basic properties such as the determinant of the DE-data are studied. Using the double Ore extension, we construct 26 families of Artin-Schelter regular algebras of global dimension four in a seque...

The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values w...

There is emerging evidence that tungsten has toxic health effects. We summarize the recent tungsten toxicity research in this short review. Tungsten is widely used in many commercial and military applications because it has the second highest melting temperature of any element. Consequently, it is important to elucidate the potential health effects of tungsten.

V. Brožek, T. F. Kubatík, Institute of Plasma Physics CAS v.v.i. Prague, Czech Republic M. Vokáč, J. Kolísko, P. Pokorný, Czech Technical University Klokner Institute, Prague. Tungsten fibers have high tensile strength but a poor oxidation resistance at elevated temperatures. Using this first characteristic and to prevent oxidation of tungsten coated composite materials in which the primary req...