33 research outputs found

    Predicting the Saturated Hydraulic Conductivity of Clayey Soils and Clayey or Silty Sands

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    Predictive models able to provide a reliable estimate of hydraulic conductivity can be useful in various geotechnical applications. Since most of the existing predictive methods for saturated hydraulic conductivity estimation are valid only for a limited range of soils or can be applied under certain restrictive conditions, a new method applicable to clayey soils and clayey or silty sands having a wide range of values of soil index properties is proposed in this study. For this purpose, 329 saturated hydraulic conductivity values, obtained by laboratory tests carried out on different soils, were collected in a database and used to develop five equations using a multiple regression approach. Each equation correlates the hydraulic conductivity with one or more geotechnical parameters. An equation was developed that predicts, within an order of magnitude, the saturated hydraulic conductivity in the range from 1.2 × 10−11 to 3.9 × 10−6 m/s, based on simple geotechnical parameters (i.e., clay content, void ratio, plastic limit, and silt content)

    Effects of dietary level of pantothenic acid and sex on carcass, meat quality traits and fatty acid composition of thigh subcutaneous adipose tissue in Italian heavy pigs.

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    Two trials were carried out to evaluate the effects of i) supranutritional doses of pantothenic acid (PA) and ii) sex on carcass, meat quality and fatty acid (FA) composition of subcutaneous adipose tissue in Italian heavy pig. In trial 1, 59 Duroc x (LxLW) pigs were fed the same diet containing either 10 [in the control (C) group] or 110 ppm [in the treatment (T) group] PA, from 107 to 168 kg live weight. At slaughtering, forty carcasses were sampled randomly. The T carcasses had lower backfat thickness (P<0.05), lower incidence of adipose cuts (P<0.05), higher lean cuts percentage (63.09 vs 60.64%; P<0.01) and lean meat yield (P<0.07). In trial 2, 42 pigs [Dumeco Cofok x (LxLW)], evenly divided into three groups, were fed the same feed containing respectively 10 (C), 60 (T1) and 110 ppm (T2) PA, from 95 to 165 kg live weight. The treatment lowered total adipose cuts yield (P<0.05) and increased lean/adipose cuts ratio (P<0.07). In the outer layer of thighs subcutaneous adipose tissue, the treatment raised polyunsaturated FA content (P<0.01), unsaturation coefficient (P<0.01) and polyunsaturated/saturated (P/S) FA ratio (P<0.05). In the inner layer, the treatment led to a lower saturated FA (P<0.05) and higher polyunsaturated FA content (P<0.01). In both trials, females generally provided leaner carcasses. In neither trials, vitamin level affected meat quality. Thus, feeding high levels of PA to heavy pigs can yield more valuable carcasses without affecting meat quality. However, effects on FA composition suggest caution in adopting this practice in the Italian heavy pig production

    Natural complementary feeds in gestating and lactating sows: effects on performance and metabolic profile

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    Gestating and lactating sows were fed natural complementary feed with the aim to improve performance and metabolic profil

    Shelf life of pork from five different quality classes

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    A total of 117 loins were selected on the cutting line at 24 h post-mortem to study the long term shelf life (35 days, 4 °C) of vacuum packaged pork from five different quality classes (PSE: pale, soft, exudative; PFN: pale, firm, non-exudative; RSE: red, soft, exudative; RFN: red, firm, non-exudative; and DFD: dark, firm, dry). The microbial load at 0 d was not significantly different (P > 0.05) among the pork quality classes, indicating that the initial microflora was influenced by the dressing conditions at the plant, not by the meat quality class. But after 35 d of storage, total aerobic mesophilic and presumptive lactic acid bacteria counts were higher (P < 0.05) in DFD pork due to its higher ultimate pH. RSE was the second quality class most susceptible to spoilage, whereas PFN, RFN and PSE pork had similar microbial loads. Further research is needed to elucidate the causes of the shorter shelf life in RSE pork

    Preliminary investigation of the use of digital image analysis for raw ham evaluation

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    In order to find objective parameters for the evaluation of pig thighs to be used for PDO processing, digital images of the external surface of 384 left thighs were acquired, to be used for multivariate image analysis. The following parameters were also measured on the same samples: weight, length, circumference, thickness of fat and thigh, globosity index and colour of skin. Moreover, a subjective evaluation of veining and red skin defects was also made by an expert assessor. Multivariate analysis of the digital images showed a separation of the analysed samples in two clusters, whose differences were then investigated on the basis of the other traits. Various differences between the two clusters where found, mainly for the size-related parameters

    Gold Derivatives Development as Prospective Anticancer Drugs for Breast Cancer Treatment

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    Commonly used anticancer drugs are cisplatin and other platinum‐based drugs. However, the use of these drugs in chemotherapy causes numerous side effects and the onset of frequent drug resistance phenomena. This review summarizes the most recent results on the gold derivatives used for their significant inhibitory effects on the in vitro proliferation of breast cancer cell models and for the consequences deriving from morphological changes in the same cells. In particular, the study discusses the antitumor activity of gold nanoparticles, gold (I) and (III) compounds, gold complexes and carbene‐based gold complexes, compared with cisplatin. The results of screening studies of cytotoxicity and antitumor activity for the gold derivatives show that the death of cancer cells can occur intrinsically by apoptosis. Recent research has shown that gold (III) compounds with square planar geometries, such as that of cisplatin, can intercalate the DNA and provide novel anticancer agents. The gold derivatives described can make an important contribution to expanding the knowledge of medicinal bioorganometallic chemistry and broadening the range of anticancer agents available, offering improved characteristics, such as increased activity and/or selectivity, and paving the way for further discoveries and applications

    Predicting the Saturated Hydraulic Conductivity of Clayey Soils and Clayey or Silty Sands

    No full text
    Predictive models able to provide a reliable estimate of hydraulic conductivity can be useful in various geotechnical applications. Since most of the existing predictive methods for saturated hydraulic conductivity estimation are valid only for a limited range of soils or can be applied under certain restrictive conditions, a new method applicable to clayey soils and clayey or silty sands having a wide range of values of soil index properties is proposed in this study. For this purpose, 329 saturated hydraulic conductivity values, obtained by laboratory tests carried out on different soils, were collected in a database and used to develop five equations using a multiple regression approach. Each equation correlates the hydraulic conductivity with one or more geotechnical parameters. An equation was developed that predicts, within an order of magnitude, the saturated hydraulic conductivity in the range from 1.2 &times; 10&minus;11 to 3.9 &times; 10&minus;6 m/s, based on simple geotechnical parameters (i.e., clay content, void ratio, plastic limit, and silt content)

    Sviluppo di una equazione di stima dello spessore del grasso di copertura della coscia suina

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    This research aimed to develop a simple mathematical model able to predict the subcutaneous fat thickness of pig thighs starting from the carcass traits as weight, backfat and l.dorsi thickness, and weight of the trimmed thighs. A stepping model-building technique using the General Regression Model method, involving two steps, was implemented. Firstly, the best fit equation was developed which was able to describe relationships among the investigated variables. Thereafter, a validation step, to evaluate the predictive ability of the model, was performed against a set of independent data from that used in building step. Results proved that both the quadratic and interactive terms of carcass traits could be successfully used to predict the subcutaneous fat thickness of pig thighs. About 82% of the predicted data were in agreement with the experimental measurements

    Reactive and Hydraulic Behavior of Permeable Reactive Barriers Constituted by Fe0 and Granular Mixtures of Fe0/Pumice

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    Abstract The objective of the present work is to analyze, by means of column tests, the reactivity and hydraulic long term behavior of the zero valent iron (Fe 0 ) and of a granular mixture Fe 0 /pumice, for the remediation, through the Permeable Reactive Barriers technology, of nickel contaminated groundwater. The reactive behavior was studied by analyzing nickel concentration data, through a first order kinetic model in order to determine the thickness of a hypothetical PRB and its variation over time. The hydraulic conductivity behavior was studied through a numerical-statistical geometrical model developed by the authors. Expansive iron corrosion, precipitation of reaction products and gas formation are the processes considered
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