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51.

Irrigated agriculture plays a vital role for the socio-economic development of the Mediterranean area, although it has significant impacts on both water and energy resources. Therefore, in a context in which water resources are also experiencing increasing pressures, there is an urgent need for supporting their sustainable management. This may be an extremely challenging task, especially at the local scale, due to the several interconnected dynamics affecting the state of a complex irrigation system. In fact, multiple actors are involved in decision-making processes, and the use of natural resources (and their mutual interactions) strongly depends on their behaviors, which affect the system as a whole. In this context, the present study proposes an integrated methodology, based on the Water Energy Food Nexus (WEFN), specifically focused on the sustainable management of water resources for irrigation. Firstly, a model based on Causal Loop Diagrams (CLD) is developed in order to get a deep insight into the key dynamics behind a complex irrigation system. Secondly, three indices based on the “footprint” concept are identified, in order to synthesize such dynamics. The integration of these two approaches support investigating the whole system and, particularly, understanding the influence of multiple decisional actors on it, as well as the role of a set of key drivers and constraints. This might also allow drawing some relevant conclusions, useful for supporting effective decisions oriented to a sustainable water resources management. Specific reference is made to a case study, the Capitanata irrigation system, located in the Southern Italy.

  相似文献   
52.
Hierarchical clustering is a common procedure for identifying structure in a dataset, and this is frequently used for organizing genomic data. Although more advanced clustering algorithms are available, the simplicity and visual appeal of hierarchical clustering have made it ubiquitous in gene expression data analysis. Hence, even minor improvements in this framework would have significant impact. There is currently no simple and systematic way of assessing and displaying the significance of various clusters in a resulting dendrogram without making certain distributional assumptions or ignoring gene-specific variances. In this work, we introduce a permutation test based on comparing the within-cluster structure of the observed data with those of sample datasets obtained by permuting the cluster membership. We carry out this test at each node of the dendrogram using a statistic derived from the singular value decomposition of variance matrices. The p-values thus obtained provide insight into the significance of each cluster division. Given these values, one can also modify the dendrogram by combining non-significant branches. By adjusting the cut-off level of significance for branches, one can produce dendrograms with a desired level of detail for ease of interpretation. We demonstrate the usefulness of this approach by applying it to illustrative datasets.  相似文献   
53.
Thermal radiative characteristics of packed beds containing a mixture of polydispersed SiO2, ZnO, and C particles are determined numerically by employing the Monte Carlo technique, which is validated with the experimentally measured overall transmittance. A radiative heat transfer model is formulated for a pseudo-continuum multi-component medium of Mie-scattering particles. Good agreement is achieved by incorporating approximate phase functions that reproduce the experimentally observed preference for forward scattering.  相似文献   
54.
The system for controlled filling of the nested flexible scintillator containment vessels in the Borexino solar neutrino detector is described. The design and operation principles of pressure and shape monitoring systems are presented for gas filling, gas displacement by water, and water displacement by scintillator. System specifications for safety against overstressing the flexible nylon vessels are defined as well as leak-tightness and cleanliness requirements. The fluid-filling system was a major engineering challenge for the Borexino detector.  相似文献   
55.
Tartaric and malic acid solutions were tested to extract anthocyanins from eggplant peel by a discontinuous process to obtain a natural red colorant. Extraction optimization was carried out, using different solvents, acid concentration, temperature, time of extraction and solvent-to-solid ratio as independent variables. Tartaric acid was more efficient than malic acid in both extraction yield and rate. Comparative tests were carried out using acidified ethanol as solvent. Delphinidin-3-rutinoside was extracted and identified as the major anthocyanin in eggplant peel. Concentration of different extracts from eggplant peel was carried out using EXA-31, a methacrylic food grade resin, the best performing resin to obtain highly concentrated extracts.  相似文献   
56.
The analysis of the infinite homogeneous reactor can be useful to have a quick understanding of nuclear reactor phenomena. Thanks to the fact that the neutron emission spectrum from fission is modeled in order to depend neither on the energy of the incident neutron nor on the fissioning nuclide, the critical neutron balance equation can be transformed from an eigenvalue problem to a simple inhomogeneous system. Similar considerations can be addressed to the adjoint problem and to the generalized importance, which can be computed with direct expressions. After having derived the equations relative to the above quantities, we apply them to the investigation of some features of the neutron spectrum in UO2 and MOX fuel. We deduce some relationships between the properties of the medium and the neutron spectrum, such as the independence of the neutron spectrum from the fission cross section and the neutron multiplicity. We show also in which extent these conclusions can be applied to real reactors.  相似文献   
57.
A room temperature conductivity maximum was recognized in the system AgI:Ag2O.B2O3 at 78.8 mole% AgI, the mobile species being silver ions.X-rays diffraction and DTA showed the glass-like nature of this material which maintains its good electrochemical performances in the temperature range 25–230°. The discharge behaviour of solid state galvanic cells containing this material is close to that obtained from 4AgI:Ag2WO4.  相似文献   
58.
In this paper we present calculations of ballistic transport in molecular wires. The calculations are performed using an approximated version of the GW correction in the plasmon-pole framework, which is used to improve the starting Density Functional Theory energy spectrum of the molecule between metallic leads. We show that this correction reduces the error of the correlation part for the electron energy. Finally a model with complex bands is implemented in order to get the damping regime for long polymers.  相似文献   
59.
Tylosin is one of the most commonly used antimicrobial drugs from the macrolide family and in broiler chickens it is used specially for the treatment of infectious pathologies. The poultry industry produces several by-products, among which feathers account for up to 7% of a chicken’s live weight, thus they amount to a substantial mass across the whole industry. Feathers have been repurposed as an animal feed ingredient by making them feather meal. Therefore, the presence of high concentrations of residues from antimicrobial drugs in feathers might pose a risk to global public health, due to re-entry of these residues into the food chain. This work aimed to characterise the depletion behaviour of tylosin in feather samples, while considering its depletion in muscle and liver tissue samples as a reference point. To achieve this goal, we have implemented and validated an analytical methodology suitable for detecting and quantifying tylosin in these matrices. Sixty broiler chickens, raised under controlled conditions, received an oral dose of 32 mg kg-1 of tylosin for 5 days. Tylosin was quantified in muscle, liver and feathers by liquid chromatography coupled with a photodiode array detector (HPLC-DAD). High concentrations of tylosin were detected in feather samples over the whole experimental period after completing both the therapy and the recommended withdrawal time (WDT). On the other hand, tylosin concentrations in muscle and liver tissue samples fell below the limit of detection of this method on the first sampling day. Our results indicate that the WDT for feather samples is 27 days, hence using feather meal for the formulation of animal diets or for other agricultural purposes could contaminate with antimicrobial residues either other livestock species or the environment. In consequence, we recommend monitoring this matrix when birds have been treated with tylosin, within the context of poultry farming.  相似文献   
60.
Protein adsorption is the first step involved in establishing a suitable integration between a biomaterial and host tissue. It is therefore of highest interest to know the electric charge of proteins present in the relevant medium to be able to predict the behaviour of cells on given surfaces. In this study, electrophoretic deposition (EPD) was used as a simple method to identify the charge of proteins present in biological medium. In the model experiment carried out here, EPD was conducted using a biological medium containing 10% fetal calf serum (FCS) and the charge of the protein was determined by examining the migration of the protein in the EPD cell under a certain applied voltage. In addition, the suitability of EPD of proteins to deliver tailored surfaces for enhanced bioactivity or for controlled deposition of protein films on metallic surfaces was explored.  相似文献   
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