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81.
Lloyd S. Nelson Paul W. Brooks Riccardo Bonazza Michael L. Corradini 《Metallurgical and Materials Transactions B》1999,30(6):1083-1088
We have developed a simple and inexpensive encapsulated mechanical impactor that can be operated under water. The unit reproducibly
generates upward-directed pressure transients in the water with peaks of approximately 0.13 MPa measured 100 mm above its
surface. These pulses have been used to trigger steam explosions of drops of a molten ferrosilicon alloy when they are either
just above the unit in free fall through the water or shortly after they land on its surface.
The impactor is study, reliable, safe, and environmentally neutral and resets for reuse within seconds. Compared to other
triggering techniques, the impactor does not generate light, bubbles, or strong water motion that obscure or appreciably affect
the initiation or early stages of the steam explosions. This permits good imaging and measurements at essentially all times
during the triggering and subsequent development of the explosions. 相似文献
82.
Chakra Wijesundera Claudio Ceccato Peter Fagan Zhiping Shen Wayne Burton Phil Salisbury 《Journal of the American Oil Chemists' Society》2008,85(8):693-699
Canola-quality Indian mustard (Brassica juncea) is being developed as a complimentary oilseed crop to canola (Brassica napus) for cultivation in hot and low-rainfall areas, where canola does not perform well. In Australia, several B. juncea breeding lines have been developed for commercial cultivation and for eventual processing as canola oil. However, there still
are significant species-based differences in the fatty acid composition with B. juncea containing lower levels of linoleic acid and higher levels of oleic and linolenic acids compared with B. napus. This has raised concern about possible oxidative stability differences between the oils. Oils (unrefined) extracted from
different breeding lines of each species were subjected to accelerated autoxidation, and development of oxidative rancidity
was assessed by four separate techniques: depletion of polyunsaturated fatty acids, depletion of tocopherol, development of
primary oxidation products, and development of secondary oxidation products (propanal and hexanal). All the tests showed that
the newly developed B. juncea oils are more stable to autoxidation than conventional canola (B. napus) oil, despite containing marginally higher linolenic levels. Oxidative stability does not appear to be a barrier to using
oils from these emerging lines of B. juncea for partial or full replacement of conventional canola oil. 相似文献
83.
Ivano Camoni Riccardo Fabbrini Leonello Attias Alfonso Di Muccio Elvira Cecere Antonio Consolino Francesca Roberti 《Food Additives & Contaminants》2001,18(10):932-936
In 1997 the Italian monitoring programme for pesticide residues in food comprised 7951 samples of 152 different foods for which a total of 275 pesticides were analysed. For 90 pesticides, the National Estimated Daily Intakes (NEDIs) were calculated by using the 90th percentile value and the food consumption data for the general Italian population. The calculated NEDIs were found to represent only a small portion of the respective Acceptable Daily Intake (ADI). 相似文献
84.
Aldo Todaro Rosa Palmeri Riccardo N. Barbagallo Pier Giorgio Pifferi Giovanni Spagna 《Food chemistry》2008
β-Glucosidase (EC 3.2.1.21) (β-G) from different sources were tested to increase the trans-resveratrol in some Sicilian wines by hydrolysing resveratrol glucoside. β-G from Aspergillus niger mould was tested as a crude and purified enzyme, and compared with the same enzyme from Saccharomyces cerevisiae yeast. Specific purification served to eliminate collateral enzyme activities so that β-G could be used simply and economically. Aspergillus niger β-G produced trans-resveratrol increases of up to 75%, with no change in physico-chemical properties and bouquet, and an increase in health and nutritional properties. S. cerevisiae β-G raised free-terpenol levels, but impaired wine colour due to anthocyanase activity. 相似文献
85.
Mamo Di Lella Riccardo Ramin 《变频器世界》2008,(11):106-107
当我们谈论效率时,我们主要指的是电力效率。然而,这种用法并不是效率一次本身的完整含义。在电力电子应用巾,工程师在开发新产品过程中的追求的主要目标是以最大限度地发挥不同类型的效率,如电效率和热效率,以及优化谐波失真和产品整体的尺寸。 相似文献
86.
This study aims to numerically and experimentally investigate the response of a medium strength rock material under unconfined compression loading up to failure. The unconfined compressive strength (UCS) is one of the most important parameters in characterising rock material behaviour. Hence the UCS is crucial in understanding the failure mechanism of fractured rocks. An effective approach to determine the UCS and to investigate the behaviours of rock materials under unconfined compression is essential in the majority of research fields of rock mechanics. The experimental configuration for the unconfined compression test, suggested by the protocols of the ASTM standard, has some limitations which affect the accuracy in determination of the real UCS. Among several alternative configurations proposed, the Mogi's configuration seems to be the most appropriate one. Therefore, the ASTM and Mogi's configurations were used to perform the tests on a medium strength rock material, i.e. Pietra Serena sandstone. The results using two configurations were discussed in terms of the differences. The tests were also replicated in LS-DYNA using a finite element method (FEM) coupled smooth particle hydrodynamics (SPH) technique. This technique is employed in this study due to its capabilities to cope with large deformation issues related to the rocks. An advanced material model, called the Karagozian and Case Concrete (KCC) model, is implemented in the numerical simulations. The KCC model consists of three independent fixed failure surfaces and it can consider the damage accumulation based on the current state of stress among these failure surfaces. An equation-of-state (EOS) is used in conjunction with KCC material model for decoupling the volumetric and deviatoric responses. The numerical and experimental results were finally compared with the focus on the stress–strain diagram and the failure patterns. The comparison shows that the numerical results are in good agreement with the experimental results. 相似文献
87.
Ionic Polymer–Metal Composites (IPMCs) are electro-active polymers transforming mechanical forces into electric signals and vice versa. This paper proposes an improved electro-mechanical grey-box model for IPMC membrane working as actuator. In particular the IPMC nonlinearity has been characterized through experimentation and included within the electric model. Moreover identification of the model parameters has been performed via optimization algorithms using both single- and multi-objective formulation. Minimization was attained via the Nelder–Mead simplex and the Genetic Algorithms considering as cost functions the error between the experimental and modeled absorbed current and the error between experimental and modeled displacement. The obtained results for the different formulations have been then compared. 相似文献
88.
Changes in olive oil volatile organic compounds induced by water status and light environment in canopies of Olea europaea L. trees 下载免费PDF全文
89.
Riccardo Bernardini Jelena Kova<cević 《Multidimensional Systems and Signal Processing》1996,7(3-4):331-369
We present a new method for constructing local orthogonal bases, both in continuous and discrete time. All basis functions are obtained from a single prototype window, and there exists a fast algorithm for implementation. The approach is very general and can handle a large variety of cases interesting for applications, such as audio and image coding. 相似文献
90.
In this work, a possible way for partial CO2 emissions reduction from gas turbine exhausts by co-firing with biomass is investigated. The basic principle is the recirculation of a fraction of the exhausts (still rich in oxygen) to a gasifier, in order to produce syngas to mix with natural gas fuel. As biomass is a CO2 neutral fuel, the fraction of replaced natural gas is a measure of CO2 removal potential of the powerplant. 相似文献