Silver as Anode in Cryolite—Alumina-Based Melts

The anodic behaviour of silver was investigated in cryolite—alumina-based melt. Silver has a lower melting point (ca. 960◦C) than the other metals considered as possible inert materials for aluminium electrolysis. The working temperature used in aluminium industry is approximately 960◦C, depending on the melt composition. Therefore, the stability of silver during the anodic process was tested at 870◦C in an acidic electrolyte consisting of 65.5 mass % Na3AlF6 + 22.9 mass % AlF3 + 5.7 mass % CaF2 + 3.9 mass % LiF + 2 mass % Al2O3 with the melting point ca. 850◦C. The electrolyte without alumina was prepared as well, with the melting point ca. 860◦C. The resulting cryolite ratio (CR = n(NaF)/n(AlF3)) for both electrolytes was equal to 1.6. The behaviour of the silver anode was studied by voltammetry measurements. The electrochemical study showed that an oxidation reaction occurred at a potential below the oxygen evolution potential. Silver was not found to be stable under oxygen evolution. The degradation of the silver anode was apparent after electrolysis

COOPERATION BETWEEN SLOVAKIA AND NEIGHBOURING COUNTRIES WITHIN ELECTRONIC FEE COLLECTION

Cooperation between the two subjects is important in any human activity and as well as electronic fee collection. It helps to improve all the final indicators. The article deals with the areas of a possible cooperation between Slovakia and neighbouring countries in many fields

PRIESTUPKY V RÁMCI ELEKTRONICKÉHO VÝBERU MÝTA

Efektívne fungujúci systém elektronického výberu mýta obsahuje aj oblasť kontroly a dohľadu. Je to záverečná časť celého systému, bez ktorej by systém nemohol správne a účinne fungovať. Článok sa zaoberá problematikou priestupkov. Všeobecne postupu ako sa priestupok zisťuje, identifikuje vozidlo a vodič až po postup vymáhania pokuty. Posledná časť sa venuje priestupkom v rámci elektronického výberu mýta v Slovenskej republike a skúsenosťami zo zahraničia.Effective system of electronic fee collection contains enforcement, too. It is a final part of the entire system without which this system could not function rightly and effectively. The article deals with offences. In general how can be the offence recognized, the vehicle and driver identified and the process of penalty recovery. The final part contains offences including electronic fee collection in Slovak republic and experience in foreign countries

Scholarly Program Notes on the Graduate Voice Recital of Laura Kucharik

This document is a discussion of the repertoire performed on my graduate voice recital. The program consists of “Erbarme Dich, mein Gott” from Johann Sebastian Bach’s St. Matthew’s Passion; three French mélodies by Franz Liszt: “S’il est un charmant gazon,” “Comment disaient-ils,” “Oh, quand je dors”; Lee Hoiby’s Three Ages of Woman, a setting of three poems by Elizabeth Bishop; Siete Canciones Populares Españolas by Manuel de Falla; four songs by Richard Strauss: “Zueignung,” “Allerseelen,” “Die Nacht,” “Befreit”; and “Non píu mesta,” the finale of the opera La Cenerentola by Gioacchino Rossini. My document contains limited biographical information, more specifically noting the significance of the composition within the life and career of the composer. For the Bach and Rossini pieces, both excerpted from a larger work, I discuss their roles within the respective works. I explore the origin or author of the song text, as well as analyzing and interpreting the text and its relationship to the music—incorporating my original analyses with published scholarly commentary. Finally, I consider appropriate performance practices for the selected works

Assessing the Potential to Decrease the Gulf of Mexico Hypoxic Zone with Midwest US Perennial Cellulosic Feedstock Production

The goal of this research was to determine the changes in streamflow, dissolved inorganic nitrogen (DIN) leaching and export to the Gulf of Mexico associated with a range of large-scale dedicated perennial cellulosic bioenergy production scenarios within in the Mississippi–Atchafalaya River Basin (MARB). To achieve this goal, we used Agro-IBIS, a vegetation model capable of simulating the biogeochemistry of row crops, miscanthus and switchgrass, coupled with THMB, a hydrology model capable of simulating streamflow and DIN export. Simulations were conducted at varying fertilizer application rates (0–200 kg N ha -1) and fractional replacement (5–25%) of current row crops with miscanthus or switchgrass across the MARB. The analysis also includes two scenarios where miscanthus and switchgrass (MRX and MRS, respectively) each replace the ca. 40% of maize production currently devoted to ethanol. Across the scenarios, there were minor reductions in runoff and streamflow throughout the MARB, with the largest differences (ca. 6%) occurring for miscanthus at the highest fractional replacement scenarios in drier portions of the region. However, differences in total MARB discharge at the basin outlet were less than 1.5% even in the MRX scenario. Reductions in DIN export were much larger on a percentage basis than reductions in runoff, with the highest replacement scenarios decreasing long-term mean DIN export by ca. 15% and 20% for switchgrass and miscanthus, respectively. Fertilization scenarios show that significant reductions in DIN leaching are possible even with application rates of 100 and 150 kg N ha -1 for switchgrass and miscanthus, respectively. These results indicate that, given targeted management strategies, there is potential for miscanthus and switchgrass to provide key ecosystem services by reducing the export of DIN, while avoiding hydrologic impacts of reduced streamflow

Multidimensional first and second order symmetric strang splitting for hyperbolic systems

We propose an algebraic basis for symmetric Strang splitting for first and second order accurate schemes for hyperbolic systems in N dimensions. Examples are given for two and three dimensions. Optimal stability is shown for symmetric systems. Lack of strong stability is shown for a non-symmetric example. Some numerical examples are presented for some Euler-like constant coefficient problems