Assessment of Water Quality After 10 Years of Reclaimed Water Injection: The Nardò Fractured Aquifer (Southern Italy)

Experimental studies have been carried out in a fractured coastal aquifer of the Salento region (Nardò, Italy), which has been subjected to 12,000 m³/day of treated municipal waste water injected into a natural sinkhole since 1991. The analytical parameters of ground water sampled in 30 monitoring wells in the area down gradient from the sinkhole, taking into account the direction of ground water flow, have been compared before and after injection. The water table mound (1.5 m), the reduction of sea water extent (2 km), and the spreading of injected pollutants were evaluated by means of a mathematical model. The predicted values in the monitoring wells were adjusted to inorganic nitrogen biodegradation using transformation rates developed in laboratory tests. After 10 years, the injection has increased the volume of the available resource for agricultural and drinking water use, without any notable decrease in the preexisting ground water quality. Moreover, to preserve water resources from pollution, the mathematical model allowed the maximum constituent concentrations (standards) in waste water reclamation for recharge to be identified. A precautionary area around the sinkhole was also defined so that withdrawal prohibition could be implemented to avoid risks to human health.     

The one-point PDF of the initial conditions of our local Universe from the IRAS PSC redshift catalogue

The algorithm ztrace of Monaco & Efstathiou is applied to the IRAS PSCz catalogue to reconstruct the initial conditions of our local Universe with a resolution down to ~5  h ¹ Mpc. The one-point probability distribution function (PDF) of the reconstructed initial conditions is consistent with the assumptions that: (i) IRAS galaxies trace mass on scales of ~5  h ¹ Mpc and (ii) the statistics of the primordial density fluctuations are Gaussian. We use simulated PSCz catalogues, constructed from N -body simulations with Gaussian initial conditions, to show that local non-linear bias can cause the recovered initial PDF (assuming no bias) to be non-Gaussian. However, for plausible bias models, the distortions of the recovered PDF would be difficult to detect using the volume finely sampled by the PSCz catalogue. So, for Gaussian initial conditions, a range of bias models remain compatible with our PSCz reconstruction results.     

Uplift rates defined by U-series and 14C ages of serpulid-encrusted speleothems from submerged caves near Siracusa,Sicily (Italy)

We have established a plausible rate of uplift near Siracusa in southeastern Sicily (Italy) over the last glacial–interglacial cycle using U-series ages of submerged speleothem calcite and ¹⁴C ages of calcite serpulid layers that encrust the speleothems during cave submergence. The precisely determined ages of these sea level benchmarks were compared with expected relative sea level position based on glacio-hydro-isostatic modeling to assess the rate of uplift in this region. When combined with the age of various late Holocene archaeological sites that have been recently described and characterized in terms of their functional position relative to sea level these data collectively define a rate of uplift ≤0.4 mm a^?1 along this portion of the Sicilian coastline. These results are consistent with an age assignment of marine isotope stage (MIS) 5.3 or 5.5 for the Akradina terrace, which in turn places temporal constraints on paleoshorelines above and below this level.     

Using unsteady-state water level data to estimate channel roughness and discharge hydrograph

A novel methodology for simultaneous discharge and channel roughness estimation is developed and applied to data sets available at three experimental sites. The methodology is based on the synchronous measurement of water level data in two river sections far some kilometers from each other, as well as on the use of a diffusive flow routing solver and does not require any direct velocity measurement. The methodology is first analyzed for the simplest case of a channel with a large slope, where the kinematic assumption holds. A sensitivity and a model error analysis are carried out in this hypothesis in order to show the stability of the results with respect to the error in the input parameters in the case of homogeneous roughness and to analyze the effect of unknown roughness heterogeneity on the estimated discharges. The methodology is then extended to the more general case of channels with mild slope and validated using field data previously collected in three Italian rivers: the Arno (in Tuscany), the Tiber (in Latium) and the Vallo di Diana, a small tributary of the Tanagro river (in Southern Italy). The performance of the proposed algorithm has been investigated according to three performance criteria estimating the quality of the match between the measured and the computed stage and discharge hydrographs. Results of the field tests can be considered good, despite the uncertainties of the field data and of the measured values.     

Field investigation on rilling in the experimental Sparacia area,South Italy

In this paper the results of a field investigation on rilling carried out in the experimental Sparacia area are reported. The measurements were made on a plot 6 m wide and 22 m long subjected to natural rainfalls. For ten rainfalls the total soil loss (interrill and rill erosion) was collected in a storage system consisting of two tanks arranged in series at the base of the plot. Rill morphology (rill length and cross‐sections) was measured for five rainfall events, while the rill profile was surveyed for three events. First the contribution of each component (rill and interrill erosion) to total soil loss was established. Then the analysis allowed establishment of a power relationship between the rill length and the rill volume. Finally, for three events detailed information on rill erosion and rill morphology allowed verification of the applicability of WEPP and estimation of the rill erodibility constant. Copyright © 2007 John Wiley & Sons, Ltd.     

Transport of suspended sediments under the influence of bank macro‐roughness

River restoration works often include measures to promote morphological diversity and enhance habitat suitability. One of these measures is the creation of macro‐roughness elements, such as lateral cavities and embayments, in the banks of channelized rivers. However, in flows that are heavily charged with fine sediments in suspension, such as glacier‐fed streams and very low‐gradient reaches of large catchment rivers, these lateral cavities may trap these sediments. Consequently, the morphological changes may be affected, and the functionality of the restoration interventions may be compromised. Herein, we analyse the influence of these macro‐roughness elements on the transport of fine sediments in the main channel. Laboratory tests with uniform flow charged with sediments in a channel with banks equipped with large‐scale rectangular roughness elements were carried out. The laboratory experiments covered a wide range of rectangular cavity geometrical configurations and shallowness ratios. The influence of key parameters such as flow shallowness, geometric ratios of the cavities and initial sediment concentration was tested. Surface particle image velocimetry, sediment samples and temporal turbidity records were collected during the experiments. The amount of sediments captured by the cavities, the temporal evolution of the concentration of sediments in suspension and the flow hydrodynamics are cross‐analysed and discussed. It is shown that the trapping efficiency of the macro‐roughness elements is a clear function of the channel geometry and the shallowness of the flow. Copyright © 2017 John Wiley & Sons, Ltd.     

Joint cosmological formation of QSOs and bulge-dominated galaxies

Older and more recent pieces of observational evidence suggest a strong connection between QSOs and galaxies; in particular, the recently discovered correlation between black hole and galactic bulge masses suggests that QSO activity is directly connected to the formation of galactic bulges. The cosmological problem of QSO formation is analysed in the framework of an analytical model for galaxy formation; for the first time a joint comparison with galaxy and QSO observables is performed. In this model it is assumed that the same physical variable that determines galaxy morphology is able to modulate the mass of the black hole responsible for QSO activity. Both halo spin and the occurrence of a major merger are considered as candidates for this role. The predictions of the model are compared with available data for the type-dependent galaxy mass functions, the star formation history of elliptical galaxies, the QSO luminosity function and its evolution (including the obscured objects contributing to the hard-X-ray background), the mass function of dormant black holes and the distribution of black hole-to-bulge mass ratios. A good agreement with observations is obtained if the halo spin modulates the efficiency of black hole formation, and if the galactic haloes at z =0 have shone in an inverted order with respect to the hierarchical one (i.e., stars and black holes in bigger galactic haloes have formed before those in smaller ones). This inversion of hierarchical order for galaxy formation, which reconciles galaxy formation with QSO evolution, is consistent with many pieces of observational evidence.     

Evaluation of cell lysis procedures and use of a micro fluidic system for an automated DNA-based cell identification in interplanetary missions

A Modular Assay System for Solar System Exploration (MASSE) is being developed to include sample handling, pre-treatment, separation and analysis of biological target compounds by both DNA and protein microarrays. To better design sensitive and accurate initial upstream sample handling of the MASSE instrument, experiments investigating the sensitivity and potential extraction bias of commercially available DNA extraction kits between classes of environmentally relevant prokaryotes such as gram-negative bacteria (Escherichia coli), gram-positive bacteria (Bacillus megatarium), and Archaea (Haloarcula marismortui) were performed. For extractions of both planktonic cultures and spiked Mars simulated regolith, FTA^® paper demonstrated the highest sensitivity, with detection as low as 1×10¹ cells and 3.3×10² cells, respectively. In addition to the highest sensitivity, custom modified application of FTA^® paper extraction protocol is the simplest in terms of incorporation into MASSE and displayed little bias in sensitivity with respect to prokaryotic cell type. The implementation of FTA paper for environmental microbiology investigations appears to be a viable and effective option potentially negating the need for other pre-concentration steps such as filtration and negating concerns regarding extraction efficiency of cells. In addition to investigations on useful technology for upstream sample handling in MASSE, we have also evaluated the potential for μTAS to be employed in the MASSE instrument by employing proprietary lab-on-a-chip development technology to investigate the potential for microfluidic cell lysis of different prokaryotic cells employing both chemical and biological lysis agents. Real-time bright-field microscopy and quantitative PMT detection indicated that that gram positive, gram negative and archaeal cells were effectively lyzed in a few seconds using the microfluidic chip protocol developed. This included employing a lysis buffer with components including lysozyme, Protease, Proteinase K, Tween-20 and TritonX-100. The effectiveness of antibiotics and other chemical lysis agents were also screened and demonstrated partial effectiveness on all three cell types. This work demonstrates a step wise approach to evaluating the efficacy and sensitivity of commercial macro-scale technology and state-of-the-art developmental microfluidic technology under consideration for incorporation into the remotely operated MASSE instrument currently under development at the Carnegie Institution of Washington.