Fe(O)/lignitic coal: an efficient and mechanically stable reactive material for purification of water containing heavy metals, radionuclides, and nitroaromatics

Mine water in the former uranium mine of K?nigstein (Saxony, Germany) contains high concentrations of acid, sulfate, iron, aluminum, various heavy metals, radionuclides, and nitroaromatics. Research has been conducted for several years to establish the extent to which reduction of pollutant concentrations can be positively influenced and accelerated by storage of reactive materials in mine cavities. Investigations were made at different scales to test and select materials with respect to maximum fixation of contaminants (underground column tests) to examine hydraulic effects (underground large-scale column tests) and to optimize material properties (laboratory tests). The investigations have shown that a mixture of Fe chips and lignitic coal is capable of efficiently cleaning acid and contaminant-containing mine water. The examined material is easily available and compatible with the environment. A large-scale application of such a reactive barrier is being considered for mine water treatment in the future and is deemed to be a reasonable conception for a safety component after conclusion of the flooding.     

In Situ Mine Water Treatment: Field Experiment at the Flooded Königstein Uranium Mine (Germany)

Within the WISMUT environmental remediation programme, the rehabilitation of the former uranium mine at Königstein is a very special case due to its use of underground leaching and its location near the Elbe River. The mine water is acidic, oxidizing, and polluted with uranium and other contaminants, and must be pumped to the surface and treated. In-situ water treatment approaches have been investigated to optimise further flooding and shorten the period of conventional water treatment. In 2010/2011, a field-scale experiment was carried out: about 120 t of alkalinity were successfully injected into the partially flooded mine. Tracer signals and geochemical reactions achieved general expectations. Based on the results, a site-specific technology concept was developed to flood the mine to its natural decant level.     

Supplier credits, limited liquidity, and timely demand information

We consider supplier-credit contracting between a manufacturer and a liquidity-constrained dealer. We show that the timeliness according to which the dealer receives demand information has a significant impact on the optimal contract. If the manufacturer cannot be sure that a dealer without liquidity has demand information when the contract is written, the optimal contract assigns the same quantity to an ignorant dealer and a dealer who knows that there are unfavorable demand conditions. However, dealers with favorable demand information are screened. If the dealer??s liquidity rises, the manufacturer proposes a contract that resembles the solution of a classic adverse selection model in the spirit of Harris et?al. (Manag Sci 28:604?C620, 1982). For high liquidity, the optimal supplier-credit contract assigns the same quantity to an ignorant dealer and dealers who have favorable demand information whereas dealers with unfavorable demand information are screened.     

Food-web structure in low- and high-dimensional trophic niche spaces

A question central to modelling and, ultimately, managing food webs concerns the dimensionality of trophic niche space, that is, the number of independent traits relevant for determining consumer–resource links. Food-web topologies can often be interpreted by assuming resource traits to be specified by points along a line and each consumer''s diet to be given by resources contained in an interval on this line. This phenomenon, called intervality, has been known for 30 years and is widely acknowledged to indicate that trophic niche space is close to one-dimensional. We show that the degrees of intervality observed in nature can be reproduced in arbitrary-dimensional trophic niche spaces, provided that the processes of evolutionary diversification and adaptation are taken into account. Contrary to expectations, intervality is least pronounced at intermediate dimensions and steadily improves towards lower- and higher-dimensional trophic niche spaces.     

The nature of the photochromism arising in the nanosized MoO3 films

We carried out the experiments which show unambiguously that not one, as it was commonly accepted, but three optical absorption bands corresponding to different color centers arise in the nanosized MoO₃ films due to hydrogen atoms. Varying the conditions for the photoinjection of hydrogen into the MoO₃ films, it is possible to change drastically the correlation between the concentrations of different arising centers, which in turn yields the great difference in the optical absorption spectra. Our findings are crucial for understanding of the nature of electrochromism and photochromism not only in MoO₃ films but also in the series of the transition metal oxide films.     

Principal Component Analysis of the Hydroxymethylation of Sugarcane Lignin: A Time-Depending Study by FTIR

Abstract

The hydroxymethylation of Acetosolv lignin from sugarcane bagasse was studied at 40°C between 0.25 and 8 h by Fourier-transformed infrared spectroscopy (FTIR). Principal Component Analysis (PCA) of the spectra has determined that addition of formaldehyde to the lignin fragments was completed within 4 h. After that time, only condensation of the fragments occurs, leading to a resol-type crosslinked resin. PCA performed in selected regions of the FTIR spectra showed that the same results are also obtained for the stretching region of O-H and C-H within the range from 2800 to 3800 cm^?1, which is not usually considered in the spectroscopic evaluations of modified lignins.     

Jet-grouting

An ultra-high pressure jet of water and air with simultaneous cement grouting is revolutionishing the practice of ground consolidation and foundation reinforcement. Swedish research has been studying this development, briefly explained here. The note report is based on a summary note issued by the Swedish Council for Building Research.     

Genome-Wide Investigation of Multifocal and Unifocal Prostate Cancer—Are They Genetically Different?

Prostate cancer is widely observed to be biologically heterogeneous. Its heterogeneity is manifested histologically as multifocal prostate cancer, which is observed more frequently than unifocal prostate cancer. The clinical and prognostic significance of either focal cancer type is not fully established. To investigate prostate cancer heterogeneity, the genetic profiles of multifocal and unifocal prostate cancers were compared. Here, we report observations deduced from tumor-tumor comparison of copy number alteration data of both focal categories. Forty-one fresh frozen prostate cancer foci from 14 multifocal prostate cancers and eight unifocal prostate cancers were subjected to copy number variation analysis with the Affymetrix SNP 6.0 microarray tool. With the investigated cases, tumors obtained from a single prostate exhibited different genetic profiles of variable degrees. Further comparison identified no distinct genetic pattern or signatures specific to multifocal or unifocal prostate cancer. Our findings suggest that samples obtained from multiple sites of a single unifocal prostate cancer show as much genetic heterogeneity and variability as separate tumors obtained from a single multifocal prostate cancer.     

Relationship between structure and electroluminescence of oligo(p-phenylenevinylene)s

The preparation of LEDs with poly( p-phenylenevinylene) (PPV) as emitting material is well established. However, due to the presence of a distribution of conjugated chain lengths in the polymer, systematic investigations of the electroluminescence with polymeric materials are difficult, as far as the optical emission is concerned. We are studying the relationship between structural variation of substituted oligo(p-phenylenevinylene)s and their electroluminescent behaviour using a series of distyrylbenzenes with a variety of substituents in order to investigate their influence on the electroluminescence (EL). Furthermore, we synthesized a homologous series of monodisperse oligo(2,5-dipropoxy-1,4-phenylenevinylene)s with up to 11 repeating units. This series covers the spectrum from monomer to polymer. The influence on the EL can be investigated by preparing single layer LEDs using vapor deposition or spincoating of the oligomers in a polystyrene (PS) matrix. The comparison of photoluminescence (PL)- and EL-spectra shows that the photophysical properties of the oligomers are strongly altered by aggregation phenomena.