In the absence of the necessary valley topography, karst depressions are sometimes used to construct conventional impoundments in order to contain tailings. Leakage is a primary concern for such impoundments. The purpose of the current study was to determine the characteristics and barrier performance of laterite mantling karst depressions, using, as an example, the Wujiwatang (WJWT) tailings impoundment, located in the Gejiu mining area, southwestern China. The geotechnical-hydrogeological properties, geochemistry, mineral compositions, and particle shapes of the laterite were investigated by geotechnical techniques, chemical analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that the laterite contained poorly sorted particles that covered a wide spectrum of grain sizes (<5 mm to <50 nm), and was unexpectedly categorized as silty clay or silt with a high liquid limit. The continuous gradation and small D90 value helped the laterite achieve saturated hydraulic conductivities in the range of <10–6 cm/s required for impoundment liners. The laterite beneath the tailings impoundment was finer-grained and had a lower permeability than that of the laterite on the depression walls within the same depression. Geochemically and mineralogically, the laterite was classified as true laterite and its major mineralogical constituents were gibbsite and goethite with chlorite occurring in trace amounts. The laterite was dominated by subspherolitic–spherolitic cohesionless grains (concretions) made up of Al, Fe, Ti, and Mn oxides and hydroxides. The laterite did not have plasticity indices in the clay range. Fortunately, slopewash prior to tailings containment selectively transported the finer oxide concretions to the depression floor, creating a natural low-permeability barrier for the WJWT tailings impoundment. This is undoubtedly important for the planning and design of future karst depression-type tailings impoundments around the world.

In a round liner barrel, the force of the closing liner is transferred by the two opposite sides of the liner wall to the teat apex. Liners with a multi-sided barrel shape close at three or more planes and distribute their force to a larger area of the teat apex. The objective of the study was to investigate effects of a liner with a multi-sided concave barrel design on the degree of teat-end hyperkeratosis, thickness and roughness, and on the time delay until thickness or roughness of teat-end hyperkeratosis responded to the experimental liner. The investigations were done on two dairy farms, one in USA and one in Germany. A split-udder arrangement of liners was used, and control treatment was a liner with round barrel shape. The test period comprised 14 weeks in the first study and 16 weeks in the second study. Thickness of teat-end hyperkeratosis was influenced by farm and test week. Roughness was influenced by farm, test week and treatment. In the first study, the incidence of rough teat-end hyperkeratosis was about 28 and 42% lower in teats milked with the experimental liner than in teats milked with the control liner by test weeks 11 and 14, respectively. In the second study, incidence of rough teat-end hyperkeratosis was rare in general, and in addition hardly occurred in teats milked with the experimental liner. The results indicate that the barrel design of the experimental liner causes similar effects on different farms but magnitude of the effect depends on initial incidence of teat end hyperkeratosis in the herd.

We report the results from an homogeneous analysis of the X-ray (ACIS-S/Chandra) data available for a sample of 52 LINER galaxies. The X-ray morphology has been classified attending to their nuclear compactness in the hard band (4.5–8.0 keV), into 2 categories: AGN-like nuclei (with a clearly identified unresolved nuclear source) and Starburst-like nuclei (without a clear nuclear source). 60% of the total sample are classified as AGNs, with a median luminosity of $\rm{L_{X}(2.0\hbox{-}10.0 keV)=2.5\times 10^{40} erg s^{-1}}$, which is an order of magnitude higher than that for SB-like nuclei. The spectral fitting allows to conclude that most of the objects need a non-negligible thermal contribution. When no spectral fitting can be performed (low signal-to-noise ratio), the Color-Color diagrams allow us to compute physical parameters such as density column, temperature of the thermal model or spectral index and therefore to analyze the origin of the X-ray emission. All X-ray morphology, spectral fitting and Color-Color diagrams allow conclude that a high percentage of LINER galaxies host AGN nuclei.

The vacuum in the mouthpiece chamber (MPC) was measured in a factorial trial with two liners (DeLaval 964008-01 and DeLaval 999007-03), two pulsator ratios (60 and 70%) and morning and evening milking over eight milkings of ten cows. Teat length and diameter were measured before and after milking, and maximum milk flow rate and depth of penetration of the teat into the teatcup were also recorded. The MPC vacuum at peak flow rate was classified as stable, at various levels, in 79% of the recordings. In the rest of the milkings the vacuum declined gradually, and this decline was associated with gradually deeper penetration of the teat into the teatcup. The DeLaval 964008-01 liner with the narrower bore and larger mouthpiece opening gave lower MPC vacuum at peak flow rate than did the wider bore DeLaval 999007-03 with the smaller mouthpiece opening. Morning milking gave higher MPC vacuum than evening milking. Increased maximum milk flow rate and increased length and diameter of the teat gave decreased MPC vacuum. The teats were longer before milking in the morning than in the evening. However, during peak flow rate, the teats had penetrated deeper into the teatcup in the evening than in the morning. A marked change in MPC vacuum in the transition to the period of flow rate can be used to identify the start of over-milking of an individual teat. A general model explaining the MPC vacuum as the outcome of the balance between air leakage past the mouthpiece lip and the leakage past the teat in the liner barrel is suggested.