Causes and Effects of Uncontrolled Water Inrush into a Decommissioned Mine Shaft

Central Europe experienced catastrophic rainfalls and flooding in 2010. This paper discusses a decommissioned shaft that was flooded by surface water, which led to displacement of shaft backfill and an inrush of large amounts of water into an underground pumping station. The weather conditions for the period preceding the inrush, the hydrogeological conditions, the quantity of water that entered the mine dewatering systems, and the underground hydraulic connections are all described. Uncontrolled inflow of water as a cause of backfill saturation and the hazard for active underground infrastructure were analysed. A need to rebuild damaged infrastructure was identified. The case study highlights the need to improve underground mine closure requirements to ensure safe conditions above ground, particularly in densely populated areas.     

A Mixed Ligand Approach for the Asymmetric Hydrogenation of 2‐Substituted Pyridinium Salts

Herein we describe a new methodology for the asymmetric hydrogenation (AH) of 2‐substituted pyridinium salts. An iridium catalyst based on a mixture of a chiral monodentate phosphoramidite and an achiral phosphine was shown to hydrogenate N‐benzyl‐2‐arylpyiridinium bromides to the corresponding N‐benzyl‐2‐arylpiperidines with full conversion and good enantioselectivity. The mechanism of the reaction under optimized conditions was investigated via kinetic measurements and isotopic labeling experiments. Our study suggests that the hydrogenation starts with a 1,4‐hydride addition and that the enantiodiscriminating step involves the reduction of an iminium intermediate.

     

Suspension flow in crystallizers with and without hydraulic classification

The main goal of this paper is to model a multiphase flow of a monodispersed suspensions in various types of crystallizers: Draft Tube Magma (DTM), Double Draft Tube (DDT) and Fluidized bed (FL). To do this, the CFD (Computational Fluid Dynamics) methods were used. The geometry of model apparatus was similar to those applied in industry. The composition of suspensions and their physical properties were the same as in practical cases.     

UNICORE 6 — Recent and Future Advancements

UNICORE is a European Grid Technology with more than 10 years of history. Originating from the Supercomputing domain, the latest version UNICORE 6 has turned into a general-purpose Grid technology that follows established standards and offers a rich set of features to its users. The paper starts with an architectural insight into UNICORE 6, highlighting the workflow features, standards and the different clients. Next, the current state of advancement is presented by describing recent developments. The paper closes with an outlook on future planned developments.     

Production of H<Subscript>2</Subscript>S and properties of sulfite reductase from selected strains of wine-producing yeasts

Correlation between H₂S productivity (p) and sulfite reductase activity (A) was estimated for seven wine-producing yeasts. It was described by a linear function p=f(A), the slope of which depended on the yeast strain. The most intensive H₂S synthesis by all the examined yeasts was observed within the early logarithmic growth phase, either in nitrogen abundance and SO₂ presence, or in nitrogen deficient and SO₂-free medium. Sulfite reductase from all the strains was optimally active at pH close to 7.4. The enzyme from cryophilic yeasts displayed maximum activity at approximately 16 °C, and from mesophiles at 22–26 °C. The preparations showed different affinities toward sulfite (K_m of 16.7–67.5 M). Values of activation energy in sulfite reduction depended on the yeast, and ranged from 14.07 to 67.04 kJ mol^–1.     

Retention of nitrogen from ground barley grain supplemented with lucerne or barley leaf juice in long-term balance experiments conducted with rats

The biological value (BV) and true digestibility of lucerne and barley juice protein mixed with ground barley grain were estimated using the Thomas-Mitchell balance method with rats. The BV with forage barley juice protein was similar to that of barley grain protein alone and was not improved by any of the applied treatments. The BV with lucerne juice protein was lower and was improved by separating the ‘brown juice’ after heat coagulation. Better results were obtained in a group fed diets with lowered levels of potassium and calcium which suggested an imbalance in the mineral content of lucerne juice; there was no difference in water consumption. The haemoglobin content of the blood of rats fed lucerne or barley juice alone was lower than that of animals fed plant juice/barley grain mixtures. No pathological lesions were observed in the guts, kidneys and livers of the rats.     

Modelling of mass loss of char particles during combustion in flow of inert material

The inspiration for this research was an attempt at the numerical simulation of the process of mass loss of char particles during its combustion in the upper zone of a CFB boiler furnace. In the first part of the research an experiment was carried out, during which singular char particles were burned in a flow of heated sand. During the course of this test manually polished spherical particles chosen from arbitrary real coal particles were used whose diameter amounted to 10 mm. The mass loss of burning particles was recorded with a tensometric branch scale. The measuring equipment applied enabled the observation of the mass loss both as a result of combustion and erosion resulting from the contact of inert material accelerated particles with the upper surface of the motionless particle being tested. The results of the experiment were compared with the results of numerical simulation, where for the first time the mass loss of a coal particle was presented as the superposition of two separate processes i.e. combustion and surface erosion. The values obtained indicated a good level of conformity which may illustrate the possibility of applying this model in real conditions.