Evaluating the Available Regional Groundwater Resources Using the Distributed Hydrogeological Budget

In this study, several hydrogeological catchments of Central Italy have been characterized focusing the attention on the presence of areas in which, over the last two decades, the hydrological equilibrium between recharge and discharge (phenomena of marked reduction of spring discharge and progressive drawdown of groundwater levels) has been compromised by overexploitation of groundwater resources. A GIS system has been used in order to develop the study and the homogenous distribution of the hydrological knowledge and of the existing imbalances has been performed. Characterizing elements of the research are: a) the definition of the hydrogeological units; b) the hydrogeological survey of around a thousand water-points; c) the monthly analysis of climatic data of numerous survey stations; d) the census and the recording of water concessions; e) the evaluation of agriculture hydro-exigency derived from the analysis of the use of soil; f) the withdrawals defined by a statistic analysis of data. These elements have allowed to define the Distributed Hydrogeological Budget which is a useful instrument to evaluate critical areas.     

Using the results of creep crack incubation tests on CrMoV steel for predicting long time creep rupture properties

The results of a series of creep crack incubation (CCI) tests have been used to examine the effectiveness of the LICON methodology for predicting long duration uniaxial rupture strength of a CrMoV steel at 550° C. The study has revealed that effective long time predictions can be made, but only with the availability of additional information including: an awareness of the short and long time rupture mechanisms and the associated multi-axial rupture criteria obeyed by the material, the results of uniaxial and multi-axial creep tests, and a knowledge of the steady state creep stress conditions existing in the testpieces (structures) forming part of the evaluation.     

Design and scale-up of pressurized fluid extractors for food and bioproducts

This article provides an in-depth review of the literature on the design, scale-up, and effects of scale on the extraction of food and bioproducts in pressurized fluid extractors. The design of pressurized fluid extraction systems such as supercritical CO₂, pressurized solvent, and pressurized low polarity water (subcritical water) are similar. Knowledge of phase equilibria, mass transfer rate, and solubility data are important first steps for the scale-up of extraction processes and equipment. The literature for the design, scale-up, and effects of scale on the extraction of bioproducts in pressurized fluid extractors is examined with particular attention to the mass transfer principal and important parameters for extraction as they relate to the design and scale-up of fixed bed pressurized fluid extractors. Often when two scales of an extractor are examined, the scale-up has not been done uniformly, leaving the effects of the scale-up on extraction in doubt. There has been some success in design of a continuous pressurized fluid extractor by utilizing a battery of vessels in series to operate on a quasi-continuous basis, and with the use of screw conveyors to produce a gas-tight plug of material, which allows the extraction to operate at the necessary elevated pressures and temperatures.     

Diffusivity maximum in a reentrant nematic phase

We report molecular dynamics simulations of confined liquid crystals using the Gay-Berne-Kihara model. Upon isobaric cooling, the standard sequence of isotropic-nematic-smectic A phase transitions is found. Upon further cooling a reentrant nematic phase occurs. We investigate the temperature dependence of the self-diffusion coefficient of the fluid in the nematic, smectic and reentrant nematic phases. We find a maximum in diffusivity upon isobaric cooling. Diffusion increases dramatically in the reentrant phase due to the high orientational molecular order. As the temperature is lowered, the diffusion coefficient follows an Arrhenius behavior. The activation energy of the reentrant phase is found in reasonable agreement with the reported experimental data. We discuss how repulsive interactions may be the underlying mechanism that could explain the occurrence of reentrant nematic behavior for polar and non-polar molecules.     

Deglutition in patients treated with reconstructive laryngectomy]

BACKGROUND: Chronic papilledema may lead to irreversible damage of optic nerve fibers. To preserve visual functions, a decompression of the optic nerve is recommended by means of a fenestration of the optic nerve sheath. In this study long-term results after optic nerve sheath fenestration in patients with idiopathic pseudotumor cerebri are reported. PATIENTS AND METHODS: 14 patients were re-examined 15 to 145 months (mean 62 months) after a fenestration of the retrobulbar optic nerve sheath on 23 eyes by a transconjunctival approach. Surgery was done to treat progressive visual loss or in severe obscurations. The patient's symptoms, visual acuity, visual fields, and ophthalmoscopic findings of the optic nerve head and the central fundus were compared to the preoperative status. RESULTS: Re-examination revealed improvement or stabilisation of objective and subjective findings in 17 eyes, one of them was operated on the more involved contralateral side only. Six eyes showed a recurrence of the papilledema without a functional change for the worse after an interval of 7 to 121 months. Three eyes of two patients ended up with optic atrophy and extensive visual loss. Preoperatively, these eyes had shown cotton wool spots in the optic nerve head and a rapid deterioration of vision. CONCLUSIONS: Fenestration of the retrobulbar optic nerve sheath can prevent further visual loss in most patients with pseudotumor cerebri, unless the eye has already become nearly blind. Postoperatively, ophthalmological controls are necessary at regular intervals because relapses after successful surgery can occur after months or years.     

Study of Drying of a Porous Medium Using Gamma-Ray Attenuation Technique

In this work the drying of porous media is considered and modeled according to Luikov equations. The experimental apparatus consists of a cylindrical porous medium positioned vertically, with its bottom closed and maintained at a constant temperature. The top surface of this porous medium is in contact with a known flow rate of dry air at room temperature. Under these conditions, the transient axial temperature and moisture concentration profiles are measured. A noninvasive technique has been used to measure the moisture content, which is based on the attenuation of a horizontal beam of gamma-rays penetrating the porous medium. The measurement of this attenuation allows determining the water content of the sample. The mathematical model has been developed using two different approaches. In the first one, the one dimensional Luikov equations are applied considering all the physical parameters as constant. In the second approach, heat and mass balance equations of this process are the simple one dimensional transient diffusion equations, considering both diffusion coefficients as adjustable function of the moisture content. As shown, this second approach is superior to the first one.     

Occurrence,Characterization, and Antimicrobial Susceptibility of Salmonella enterica in Slaughtered Pigs in Sardinia

The aim of this study was to determine Salmonella occurrence in slaughtered finishing pigs and piglets and in slaughterhouse environment in order to characterize the isolates with phenotypical (antimicrobial testing) and molecular (PFGE, MLVA) methods. Nine slaughterhouses located in Sardinia were visited. Six hundred and eight samples collected from 106 pigs and 108 environmental samples were collected and analyzed. Salmonella was isolated in 65 of 504 (12.9%) samples from finishing pigs, with an occurrence of 15.1% in colon content, 12.7% in lymph nodes and liver, and 11.1% in carcass surface samples. Salmonella was never detected in piglets. The combined results of serotyping and PFGE showed a possible self‐contamination in 71.5% of Salmonella positive carcasses of lymph nodes and/or colon content carriers, pointing out the role of healthy pigs for carcass contamination. A significantly higher (P < 0.05) occurrence was detected in finishing pigs of EC countries origin (23%) than in pigs of local farms (8%). Salmonella was also detected in 3.7% of environmental samples. The most prevalent serovar was S. Anatum, followed by S. Rissen, S. Derby, and monophasic S. Typhimurium. Resistance to at least 3 antimicrobial was observed in 97.1% of strains and 7 different patterns of multiple resistance were identified. The most common resistance was detected against sulphonamide compounds. A strict slaughterhouse application of hygiene standards is essential to control the risk of Salmonella contamination.     

Analysis of fetal sex in TCC sample DNA: a contribution to the validation of this approach

We compared two methods of collection of transcervical cell samples, mucus aspiration and cytobrush, with respect to the efficiency in determining fetal sex and we correlated the results with the week of gestation (7-11 weeks) to evaluate if the age of gestation influenced the success of the analysis. DNA extracted from TCC samples recovered by mucus aspiration (n = 27) and cytobrush (n = 36) were analysed by nested PCR to predict fetal sex. The statistical indices of sensitivity, specificity, positive predictive value and negative predictive value were determined, and compared with those of other studies previously performed. No statistically significant difference was found between the two methods of TCC sampling concerning the success of fetal sex prediction which was high for both methods (78 per cent and 89 per cent) and no correlation with the week of gestation was found. Transcervical cell sampling represents an encouraging prospect for first-trimester prenatal diagnosis even when the least invasive techniques are used.