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141.
142.
A simple model is proposed for the temperature field within an unconfined semi-infinite thick aquifer, with groundwater flowing parallel to the terrestrial heat flow in the recharge zone, and perpendicular to heat flow in the other parts of the aquifer. The results enable evaluation of the extent of the influence of the recharge zone, once the thermal and hydrological parameters are known. Beyond this zone, where thermal equilibrium between water and rock is reached, water temperature reaches the constant highest value, and water movement cannot be revealed by temperature measurements. Moreover, over,on the basis of the range of influence of the recharge zone, the regional water pore velocity can be inferred. 相似文献
143.
Following an early phase of limited activity at the University of Pisa on small stainless steel pipes containing axial cracks, in 1981 ENEA, the Italian Committee for Research and Development of Nuclear Energy and Alternative Energies, has started a massive research campaign on fracture of carbon and stainless steel piping containing through and part-through cracks loaded either under pressure or in bending. The purpose of the program was to develop a better understanding on pipes fracture behaviour in order to set new design criteria more realistic, yet conservative, than the guillotine break and prepare acceptance criteria for in-service flaws particularly under the growing pressure of IGSCC that has merciless affected worldwide practically any BWR piping system.The analysis of more than 100 tests carried out at CISE research centre, in Milano, on 4 inch, 6 inch, 8 inch and 10 inch pipes has indicated that unstable fracture requires at least 150° through wall crack under ASME maximum design stresses. The leak area, before instability takes place, is always less than 10% of the net cross section area of the pipe. This has led ENEA to consider a 10% break area as a reasonable value to calculate jet forces. Further, it was found that the net section collapse load criterion by far underestimates the actual collapse load and that 360° part-through cracks tend to switch from ductile to brittle failure mode of a pipe loaded in bending.Further work is planned for the next 3 years including high temperature tests, stainless steel weldments and HAZ tests, high compliance tests and eventually burst tests. Besides the ENEA's research program, Ansaldo AMN, the Italian Nuclear Architect Engineer, is developing theoretical studies and codes to treat the problem of pipe fracture. 相似文献
144.
Use of a toasted durum whole meal in the production of a traditional Italian pasta: chemical, mechanical, sensory and image analyses 总被引:1,自引:1,他引:0
Antonietta Baiano Clara Fares Giorgio Peri Roberto Romaniello Antonella M. Taurino Pietro Siciliano Giuseppe Gambacorta Carmela Lamacchia Sandra Pati & Ennio La Notte 《International Journal of Food Science & Technology》2008,43(9):1610-1618
The characterisation of traditional Italian pasta obtained by mixing amounts of toasted whole meal with re-milled semolina and other ingredients was obtained by means of physico-chemical, rheological, mechanical, sensory and image analyses. The toasted meal showed higher ash, fibre and protein contents than re-milled semolina. The replacement of percentages of re-milled semolina with the toasted meal and soft flour increased tenacity and decreased extensibility and strength, making the dough less suitable for pasta-making. The P / L values were indices of high starch damage. The replacement of part of re-milled semolina and water with toasted whole wheat meal, soft flour and eggs increased the optimal cooking time and the amount of water absorbed during cooking but made the other cooking parameters worse. The image analysis provided evidence of the changes induced by the use of toasted wholemeal, soft flour and eggs in the microscopic structure of pasta protein and starch. 相似文献
145.
Roberta D’Ambrosio Alessio Aghemo Raffaele De Francesco Maria Grazia Rumi Enrico Galmozzi Stella De Nicola Cristina Cheroni Paul J. Clark Guido Ronchi Pietro Lampertico Massimo Colombo 《International journal of molecular sciences》2014,15(5):7213-7224
The interleukin 28B (IL28B) rs12979860 polymorphism is associated with treatment outcome in hepatitis C virus (HCV) genotype 1 and 4 patients. Its association with the histological features of chronic hepatitis C and disease severity needs further clarifications. To assess the correlation between IL28B genotype, HCV genotype and liver biopsy findings in untreated patients.
Materials and Methods
Pre-treatment liver biopsies from 335 HCV Caucasian patients (59% males, age 50 years) enrolled in the MIST study were staged for fibrosis and inflammation according to the METAVIR and the Ishak scoring systems; steatosis was dichotomized as <5% or ≥5%. IL28B was typed by Taqman Single Nucleotide Polymorphism (SNP) genotyping assay. HCV genotype was 1 in 151 (45%), 2 in 99 (30%), 3 in 50 (15%) and 4 in 35 (10%) patients. IL28B genotype was CC in 117 (34%), CT in 166 (49%) and TT in 52 (15%). At univariate analysis, the IL28B CC genotype was associated with severe portal inflammation in HCV-1 patients (CC vs. CT/TT: 86% vs. 63%, p = 0.005), severe lobular inflammation in HCV-2 patients (CC vs. CT/TT: 44% vs. 23%, p = 0.03), and less fatty infiltration in HCV-1 patients (CC vs. CT/TT: 72% vs. 51%, p = 0.02). Despite the lack of any association between IL28B and fibrosis stage, in HCV-3 patients IL28B CC correlated with METAVIR F3–F4 (CC vs. CT/TT: 74% vs. 26%, p = 0.05). At multivariate analysis, the genotype CC remained associated with severe portal inflammation in HCV-1, only (Odds Ratio (OR): 95% Confidence Interval (CI): 3.24 (1.23–8.51)). IL28B genotype is associated with the histological features of chronic hepatitis C in a HCV genotype dependent manner, with CC genotype being independently associated with severe portal inflammation. 相似文献146.
Sérgio Trajano Franco Moreiras Antenor Braga Paraguassú Gian Franco Napa 《Bulletin of Engineering Geology and the Environment》2014,73(4):1325-1330
Polished finishing granites are greatly accepted for claddings because of the plates’ shape, design and color variety. The features depend on the geological conditions that occur during the formation process, which include the mineralogy of the stone, the fluids formed during the process, the grain size of the minerals and the way in which the minerals interact with each other. One of the noblest uses of stone plates is in non-adherent covering systems (without mortar), such as ventilated façades and pedestrian paving systems. Currently, the methodology for non-adherent systems uses the allowable stress design criteria. In recent years, the number of papers indicating reliability analysis as an important design tool for natural stones has increased. However, a lack of information concerning the design methodology still happens. Therefore, the structural properties assessed as complementing these studies were: compressive strength, three-point flexural tensile strength, Young’s modulus and Poisson’s ratio. A granite slab design example was also presented. First, the thickness of the plates was determined based on the formulation proposed by Timoshenko [Strength of materials (original language, Portuguese), Volume II. Editora Ao Livro Técnico S. A., Rio de Janeiro, 1977], using the allowable stress design criteria. Next, the reliability analysis was performed by Monte Carlo simulation. Results showed that the Desireé White granitic plate presented a higher reliability index than the Capão Bonito Red granitic plate. This result seems to be paradoxical, owing that the Capão Bonito Red presented a higher value of mean flexural strength than the Desireé White. The minimal safety factors to satisfy the target reliability value of 3.8 as recommended by the standard EN 1990:2002 (Eurocode) were found to be 2.61, 1.98 and 2.72, respectively, for the three stone types. 相似文献
147.
Dejan Radjen Martin Anderson Lars Sundström Pietro Andreani 《Analog Integrated Circuits and Signal Processing》2014,80(3):387-397
We present a 2nd-order 4-bit continuous-time (CT) delta-sigma modulator (DSM) employing a 2nd-order loop filter with a single operational amplifier. This choice strongly reduces the power consumption, since operational amplifiers are the most power hungry blocks in the DSM. The DSM has been implemented in a 65 nm CMOS process, where it occupies an area of \(0.08\,\hbox {mm}^2\) . It achieves an SNDR of 64 dB over a 500 kHz signal bandwidth with an oversampling ratio of 16. The power consumption is \(76\,\upmu \hbox {W}\) from a 800 mV power supply. The DSM figure-of-merit is 59 fJ/conversion. The CT DSM is well suited for the receiver of an ultra-low-power radio. 相似文献
148.
Luigi Mascolo Pietro Guccione Giovanni Nico Paolo Taurisano Leonardo Fazio 《International journal of imaging systems and technology》2014,24(3):239-248
The purpose of this article is to present a methodology to identify the sources of activity in brain networks from functional magnetic resonance imaging (fMRI) data using the multiset canonical correlation analysis algorithm. The aim is to lay the foundations for a screening marker to be used as indicator of mental diseases. Group analysis blind source separation methods have proved reliable to extract the latent sources underlying the brain activities but currently there is no recognized biomarker for mental disorders. Recent studies have identified alterations in the so called default mode network (DMN) that are common to several neuropsychiatric disorders, including schizophrenia. In particular, here we account for the hypothesis that the alterations in the DMN activity can be effectively highlighted by analyzing the transient states between two different tasks. A set of fMRI data acquired from 18 subjects performing working memory tasks is investigated for such purpose. Subjects are patients affected by schizophrenia for one half and healthy control subjects for the other. Under these conditions, the proposed methodology provides high discrimination performances in terms of classification error, thereby providing promising results for a preliminary tool able to monitor the disease state or to perform a prescreening for patients at risk for schizophrenia. © 2014 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 24, 239–248, 2014 相似文献
149.
Laura Mayol Daniela De Stefano Virginia Campani Francesca De Falco Eleonora Ferrari Claudia Cencetti Pietro Matricardi Luigi Maiuri Rosa Carnuccio Angela Gallo Maria Chiara Maiuri Giuseppe De Rosa 《Journal of materials science. Materials in medicine》2014,25(6):1483-1493
In this study, a sterile and biocompatible chitosan (CHI) gel for wound healing applications was formulated. CHI powder was treated in autoclave (ttCHI) to prepare sterile formulations. The heat treatment modified the CHI molecular weight, as evidenced by GPC analysis, and its physical–chemical features. Differential scanning calorimetry studies indicated that the macromolecules, before and after thermal treatment, differ in the strength of water-polymer interaction leading to different viscoelastic and flow properties. Thermally treated CHI exhibited the following effects: (i) increased the proliferation and migration of human foreskin foetal fibroblasts at 24 h; (ii) accelerated wound healing (measured as area of lesion) at 3 and 10 days in an in vivo model of pressure ulcers. These effects were linked to the increase of the hydroxyproline and haemoglobin content as well as Wnt protein expression. Moreover, we found a reduction of myeloperoxidase activity and TNF-α mRNA expression. These observations suggest the potential of this novel CHI gel in wound healing and other therapeutic applications. 相似文献
150.
Mariapaola Parisi Alberto GiaconiaSalvatore Sau Annarita SpadoniGiampaolo Caputo Pietro Tarquini 《International Journal of Hydrogen Energy》2011,36(3):2007-2013
This paper reports an investigation on the Bunsen reaction. An experimental campaign was conducted by means of a stirred reactor. Runs were carried out at a constant temperature in the 30-120 °C range, following a semi-batch procedure by feeding gaseous sulfur dioxide in an iodine/hydriodic acid/water solution. A specific analytical procedure to measure the hydriodic phase composition was implemented. It was observed that both the amount of absorbed SO2 and its conversion lowered as the temperature increased. Secondary reactions were beyond the detection limit in the reactor, even at low temperature and low iodine content. The purification of the produced hydriodic phase was also investigated. It was possible to satisfactorily reduce the impurities content without the occurrence of secondary reactions only when high temperature and high iodine content were applied. 相似文献