Quasi-Conservative Formulation of the One-Dimensional Saint-Venant–Exner Model

Coupling the Saint-Venant equations with the Exner equation a morphodynamic model is produced, which can be used to describe flow and bed evolution in natural rivers. The system of governing equations is hyperbolic and is expressed in nonconservative form. For this reason, fully primitive formulations of the model are often adopted for the solution, which however are known to incorrectly compute strength and celerity of shock waves (bores). In the present work a quasi-conservative formulation of the differential system is proposed, which aims at reducing these errors to a minimum. The performances of the model are assessed by comparison with primitive formulations applied to some schematic cases and with experimental observations obtained on a physical model of a river reach. Results are satisfactory and overcome predictions based on fully primitive formulations.     

Evidence of Phase Separation in the P-T Phase Diagram of the La0.75Ca0.25MnO3 Manganite by Infrared Measurements

Recent infrared absorption measurements performed at different pressures and temperatures on the La_0.75Ca_0.25MnO₃ manganite provided an estimate of the insulator-to-metal transition temperature T _IM(P), i.e., the P-T phase diagram of a pseudocubic manganite. Here we consider in detail the P- and T-dependence of the absorption spectral weights n ^*. The n ^*(T,P) behavior gives evidence of phase-separation between conducting and insulating domains in the P-T phase diagram, and allows to establish the occurrence of a characteristic temperature T ^* ≅ 0.6 T _IM. For T > T ^*, when insulating domains decrease on decreasing temperature or on increasing pressure, it is possible to distinguish a metallic region (connected metallic domains) for T ^* < T < T _IM, and an insulating region (disconnected metallic domains) for T > T _IM. Below T ^*, no reduction of the insulating domains, that may still exist, occurs.     

Effect of Fermentation and Drying on Procyanidins, Antiradical Activity and Reducing Properties of Cocoa Beans

This work was aimed to determine the effect of fermentation and drying on the content and profile of procyanidins (from monomers P1 to polymers P10) as well as on the antiradical and scavenging properties of cocoa beans. To this purpose, three experiments were carried out: a traditional fermentation process followed by air drying and two pilot-scale fermentation processes by either natural microbiota or starter followed by sun drying. Procyanidins were evaluated by HPLC analysis, while the total polyphenol index (TPI), the antiradical activity as well as the reducing power were determined by means of the reaction with the Folin–Ciocalteu reagent, the decolorization assays of the ABTS radical (TEAC) and the Ferric Reducing Antioxidant Power (FRAP) methods, respectively. Both the traditional and pilot-scale processes resulted to affect the profile and content of the procyanidins fractions as well as the antiradical and reducing power functionality. Drying caused a severe reduction of compounds and thus resulted to be the critical step for the loss of procyanidins and monomers in particular. The indices of functionality generally showed a decreasing trend as a consequence of processing, and their evolution was similar to that observed in procyanidins content. To study the relationship between the individual procyanidins and the antioxidant activity expressed as TEAC, FRAP and TPI, the data set were processed by modified partial least squares regression. The obtained models presented a good predictive ability. Normalised regression coefficients showed that the relative contribution of each single class of compounds to total antioxidant activity resulted as follows: P1?>?P2?>?P3?>?P4?>?P6?>?P8?>?P5?>?P7?>?P9?>>?P10.     

Influence of processing and storage on the antioxidant activity of apple derivatives

The antioxidant activity of seven apple varieties was determined on fresh fruits and processed products (dried fruits and purees) and during storage. The antioxidant activity of apples correlated with the total phenol concentration but not with ascorbic acid concentration. Apple derivatives showed a lower antioxidant activity than the counterparts of the fresh fruits and the occurrence of browning phenomena during processing resulted in lower antioxidant activity. Dried fruits showed higher antioxidant activity per gram of dried matter than fruit purees probably because of the lower total thermal effect of processing. The antioxidant activity of all products increased within the first month of storage, and then declined. The extent of early increase was related to the polyphenol content of the fruit. Packaging conditions further influenced the antioxidant activity increase during storage possibly by affecting the oxygen availability.     

Electrospun polymeric coatings on aluminum alloy as a straightforward approach for corrosion protection

Several metals and alloys are susceptible to corrosion attack and this usually implies the accurate selection of a specific material depending on the working conditions and the characteristics of the environment to which it will be exposed to. However, it could represent a restriction at the same time because a limited range of materials can be practically considered. In addition, they could be also characterized by unsuitable properties for the intended application and high costs. To address this issue, polymeric coatings exhibit high potentiality to be a valid alternative to toxic chromates, allowing to deal with the most appropriate metallic materials and affordable deposition procedures. In this work, polyvinyl alcohol (PVA) fibrous coating was successfully collected onto aluminum alloy‐6082 by means of electrospinning technique. The anticorrosion performance of the final system has been evaluated in 3 wt % NaCl solution by means of electrochemical impedance spectroscopy (EIS). To avoid PVA disintegration in aqueous environment, several crosslinking procedures were assessed using glyoxal. The two most promising ones (120°C for 60 min and 150°C for 15 min) were then considered for a further investigation. Crosslinked PVA mats showed improved properties as compared to the as‐spun case, as demonstrated by mechanical and thermal analyses. Electrochemical tests revealed that crosslinked coatings can protect aluminum substrates against corrosion, especially for the electrospun PVA coating treated at 120°C. In this case, after 270 h, a significant corrosion resistance of about 26 kΩ was recorded with respect to the blank alloy (about 3.8 kΩ). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41250.     

上海市中心某旧工业厂区改造

盐酸情人 关注细节、书法、肉体谜恋、自毁--如果把盖天柯(Francesco Gatti)的"in Factory"与彼得格林纳威(Peter Greenaway)的<枕边禁书>还有中国作家棉棉的<九个目标的欲望>放在一起比较的话,以上词汇便会跃入脑海.     

Subcutaneous lidocaine does not affect the success rate of intravenous access in children less than 24 months of age

OBJECTIVE: To determine whether subcutaneous lidocaine (SQL), when used to decrease the pain of IV catheter insertion, adversely affects IV access in children < 24 months of age. METHODS: A historically controlled comparison of IV access successes with and without SQL in children < 2 years of age was performed in a 30,000-annual-visit community hospital ED. On-site data collected at the time of IV placement included: patient age, weight, hydration status, number of attempts, and location of attempts. All patients had IV attempts made by the same emergency physician. RESULTS: A total of 110 children, mean age 9.6 +/- 6.9 months, were included in the study analysis. Of the 110, 70 had an IV catheter placed with no pretreatment, while 40 had SQL pretreatment. The average number of attempts for all patients was 1.36 +/- 0.73, with 83 (75%) performed successfully in 1 attempt and 101 (91%) within 2 attempts. The mean numbers of attempts were similar for the control and SQL groups: 1.34 vs 1.40, respectively (p = 0.68), as were the proportions successful in 1 attempt (77% vs 73%; p = 0.58) and within 2 attempts (91% vs 90%; p = 0.84). CONCLUSION: SQL use prior to an IV attempt in children < 2 years of age does not impact vascular access. A secondary finding was that vascular access with and without SQL in infants and small children generally can be accomplished in 1 attempt.     

Effect of blanching in water and sugar solutions on texture and microstructure of sliced carrots

Thermal processing of vegetables has pronounced effects on the cell structure, often negatively affecting the final textural properties of the product. In order to study the effect of thermal processing and the protective effect of sugars on the tissue, sliced carrots were subjected to blanching treatments under different time and temperature combinations both in water and in 4% sugar solutions made of trehalose or maltose. The influence of these process conditions on mass transfer, texture, and microstructure (Cryo-scanning electron microscopy) was thus investigated. The total mass loss of all the samples blanched in water was associated to their cook value (C(100)(18)) except for the overprocessed one (90 °C, 10 min) that showed a total mass change significantly lower due to water uptake. The use of trehalose and maltose in the blanching solution reduced the solute loss while increasing the water loss. Microstructural analysis of the differently blanched carrots showed detachments between adjacent cell walls as well as plasmolysis phenomena as the time and temperature of the thermal treatment were increased. A protective effect of both sugars on cell structures was observed mostly in the sample treated at 90 °C. At macroscopic level, textural changes upon blanching were observed by a penetration test. As blanching time was increased, samples processed at 75 °C showed a hardness increase, while those processed at 90 °C showed a hardness decrease. However, both trehalose and maltose did not exert significant effects on the textural properties of blanched carrots when compared with those blanched in water. Practical Application: The results of this study could offer interesting perspectives in the optimization of the heat treatments in order to preserve the quality of semi-finished processed vegetables. Furthermore, the microstructural analysis is nowadays an important investigation tool that could contribute to a deeper understanding of both the effects of processing and ingredients on the vegetable microstructure and its relationship with the changes occurring on the quality properties at macroscopic level.     

Public–private contribution to biopharmaceutical discoveries: a bibliometric analysis of biomedical research in UK

Scientometrics - Basic research creates new knowledge that fuels technological advances. However, budgetary concerns and escalating R&amp;D prices are challenging organizations to show returns...