Applying aluminum-organic matter precipitates to reduce soil permeability in-situ: A field and modeling study.

Using naturally occurring processes to modify the engineering properties of the subsurface has received increasing attention from industry and research communities as they aid in the development of cost-effective, robust and sustainable engineering technologies. In line with this trend, we propose to use precipitates of aluminum (Al) and organic matter (OM) to reduce soil permeability in-situ. This process is inspired by podzolization: a soil stratification process where a layer with low permeability is developed at depth via the precipitation of metal-OM complexes. In this study, the concept of applying Al-OM precipitates for in-situ soil permeability reduction was for the first time applied in the field. The aim of the field experiment was to create a cylindrical flow barrier in a sand layer at depth. In order to design and engineer the field application, we performed a series of scenario analyses with a site-specific 3D reactive transport model. This led to an in-situ engineering approach where a flow barrier was created by separate injection of Al and OM using a combined injection/extraction strategy. During the field application, the local variation of soil conditions required significant modifications to the design. Further scenario analyses with the model were conducted to adapt the original design and to understand the consequences of these modifications. The results show that a cylindrical flow barrier was created after an injection period of 8 days. The precipitation of Al-OM is a highly localized process, where large amount of precipitates is formed in the close vicinity of the injection filter screens. Evaluation of pumping tests that were performed after the injection activities revealed that the permeability of the treated sand was reduced to 2% of its original value. This first full-scale field test demonstrates that applying Al-OM precipitates is a suitable bio-based engineering tool to reduce soil permeability in-situ.

Regulation of tattoo ink production and the tattoo business in the US.

The production of tattoo ink and pigments in the US is unregulated. There are no guidelines or standards issued by national agencies. However, the practice of tattooing is regulated at the state and local levels but varies widely. Adverse events are addressed when a problem is reported.

Compositional dependence of the thermoelectric properties of (Sr(x)Ba(x)Yb1₋2x)(y)Co4Sb12 skutterudites.

High temperature thermoelectric (TE) properties for triple-filled skutterudites (Sr(x)Ba(x)Yb1₋2x)(y)Co4Sb12 were investigated for alloy compositions in two sections of the system: (a) for x = 0.25 with a filling fraction y ranging from 0.1 to 0.25 and (b) for 0 < x < 0.5 and y = 0.11 + 0.259x. The representation of the figure of merit, ZT, as a function of skutterudite composition, defined the compositional range (0.25 < x < 0.4; 0.18 < y < 0.24) with ZT over 1.4 at 800 K. It was shown that an enhanced TE performance for these triple-filled skutterudites is caused by low electrical resistivities and low lattice thermal conductivities, as well as by a fine tuning of the chemical composition. Low temperature measurements for the samples with the highest ZT values showed that even a small change of the filler ratios changes the contribution of scattering effects, the carrier concentration and the mobility.

Variations in concentrations and compositions of polycyclic aromatic hydrocarbons (PAHs) in coals related to the coal rank and origin.

The release of unburnt coal particles and associated polycyclic aromatic hydrocarbons (PAHs) may cause adverse impacts on the environment. This study assessed variations in the concentration and composition of PAHs in a set of fifty coal samples from eleven coal basins worldwide. The maximum PAH concentrations at high volatile bituminous rank were recorded in samples from a single basin. Considering the entire sample set, the highest PAH concentrations were in fact found outside of this rank range, suggesting that the maceral composition and thus the coal's origin also influenced PAH concentrations. The examination of the PAH compositions revealed that alkylated 2-3 ring PAHs remain dominant compounds irrespective of coal rank or origin. Multivariate analysis based on PAH and maceral content, bulk and maturity parameters allowed the recognition of seven groups with different rank and origin within the coal sample set.

Chemical pressure, dilution and disorder in the heavy fermion compounds Ce(3-x)La(x)Pd20Si6 (x=1/3, 2/3).

The heavy fermion compound Ce3Pd20Si6 is one of the rare examples of a cubic system with a readily accessible quantum critical point. Ce atoms at the two different sites 4a and 8c of the crystal structure have recently been shown to have different crystal field ground states (Γ7 and Γ8, respectively) and are assumed to be responsible for the two different low-temperature phase transitions at T(L) and T(U), which have been tentatively attributed to antiferromagnetic and antiferroquadrupolar order, respectively. Here we present electrical resistivity measurements in a wide temperature range (50 mK-300 K) on two new representatives of the La substitution series Ce(3 - x)La(x)Pd20Si6, x=1/3 and 2/3. Put in the context of previously published data our results indicate that La preferentially occupies the 4a site and that Ce ions at the 8c site have a sizably larger Kondo temperature. Low-temperature resistivity measurements in applied magnetic fields suggest that (disorder smeared) quantum critical points exist in the x=1/3 and 2/3 samples at fields below 1 T.

[An extreme case of environmental neurosis]. / Ein Fall einter "Umweltneurose" skurrilen Ausmasses.

A 64 year old female patient was diagnosed with scleroderma and has been bed-ridden for 25 years. She wears no clothing whatsoever on the grounds of an intolerance to textiles, and has spent the last eight years uninterruptedly in bed in a construction of kitchen paper towels and rubber bed sheets. A somatic disease has been be ruled out and cenesthesic schizophrenia diagnosed. As differential diagnoses, somatization, somatiform disorders and hypochondria were considered. The patient refused any psychiatric treatment.

Characterization of two D-glyceraldehyde-3-phosphate dehydrogenases from the extremely thermophilic archaebacterium Thermoproteus tenax.

Thermoproteus tenax possesses two different glyceraldehyde-3-phosphate dehydrogenases, one specific for NADP+ and the other for NAD+. NADP(H) inhibits the NAD+-specific enzyme competetively with respect to NAD+ whereas NAD(H) virtually does not interact with the NADP+-specific enzyme. Both enzymes represent homomeric tetramers with subunit molecular masses of 39 kDa (NADP+-specific enzyme) and 49 kDa (NAD+-specific enzyme), respectively. The NADP+-specific enzyme shows significant homology to the known glyceraldehyde-3-phosphate dehydrogenases from eubacteria and eukaryotes as indicated by partial sequencing. The enzymes are thermostable, the NADP+-specific enzyme with a half-life of 35 min at 100 degrees C, the NAD+-specific enzyme with a half-line of greater than or equal to 20 min at 100 degrees C, depending on the protein concentration. Both enzymes show conformational and functional changes at 60-70 degrees C.