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91.
Vincenzo M. Sglavo Paolo Bosetti Elena Trentini Michele Ceschini 《Journal of the American Ceramic Society》1999,82(8):2269-2272
A technique for precracking brittle materials is presented. This procedure, which is called the sandwiched-beam (SB) technique, allows the production of sharp through-thickness cracks with predetermined length in specimens with a rectangular section. A bar, in which an initial notch is produced by using a conventional saw, is inserted between two supporting beams and the sandwich assembly is loaded in three-point bending. Conditions can be defined that allow the stable propagation of a sharp flaw from the notch as the applied load is increased. Then, the cracked bar can be used to determine the fracture toughness. The SB technique is applied to different brittle materials, including soda-lime-silica glass, alumina, Si3 N4 , a SiC w -Si3 N4 composite, graphite, a Ti-Al intermetallic, and Carrara marble. 相似文献
92.
Acrylamide formation in a cookie system as influenced by the oil phenol profile and degree of oxidation 总被引:1,自引:0,他引:1
Gema Arribas-Lorenzo Vincenzo Fogliano Francisco J. Morales 《European Food Research and Technology》2009,229(1):63-72
The purpose of this study was to investigate the effect of the olive oil phenolic compounds as well as of thermoxidised oil
on the formation of acrylamide in a cookies system. Three virgin olive oils having different phenolic profile and a thermoxidised
sunflower oil were selected. Cookies were baked at 190 °C for different times (8–16 min) following a basic recipe where type
of oil was the variable. Additionally to acrylamide (AA), other parameters such as colour, moisture, antioxidant activity
(AOA), and hydroxymethylfurfural (HMF) were measured. Results showed that concentration and composition of phenolic moiety
of virgin olive oil significantly affect the acrylamide formation, particularly at prolonged baking time. Virgin olive oil
with a higher dihydroxy/monohydroxy ratio was more efficient in the AA mitigation and AA was reduced up to 20%. Colour and
AOA were not significantly different among the three types of oils. However, AA is dramatically increased when thermoxidised
oil is used with a parallel increase of browning and HMF. It was concluded that lipid oxidation products should be considered
as an important factor in acrylamide formation during baking of fat-rich products. 相似文献
93.
94.
Livan Fratini Vincenzo Fortunato Ruisi 《The International Journal of Advanced Manufacturing Technology》2009,43(1-2):61-66
In the paper, the growing interest on hybrid joints developed between composite panels and aluminium alloys blanks is focused. The self-piercing riveting operation is considered and its feasibility for the proposed joints verified. The most relevant process parameters were investigated in order to determine a suitable process window and, what is more, the mechanical performances of the developed joints were investigated in order to determine process parameters aimed to maximise them. Finally, the failure mechanics of the obtained joints were considered in order to highlight the mechanisms which occur and determine the lost of the load carrying capability of the joints. The developed experiments demonstrated that self-piercing riveting can be effectively used to join fibreglass composite panels and aluminium blanks. 相似文献
95.
Nello Angelucci Nicola Bianco Oronzio Manca 《International Journal of Heat and Mass Transfer》1997,40(18):1439-4491
96.
P. Vanlaeke A. Swinnen I. Haeldermans G. Vanhoyland T. Aernouts D. Cheyns C. Deibel J. DHaen P. Heremans J. Poortmans J.V. Manca 《Solar Energy Materials & Solar Cells》2006,90(14):2150-2158
The performance of organic solar cells based on the blend of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) is strongly influenced by blend composition and thermal annealing conditions. X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) diffraction measurements show that in the considered blends, ordering of P3HT plays a key role in understanding the PV-performance. It is demonstrated that the natural tendency of regioregular P3HT to crystallize is disturbed by the addition of PCBM. Annealing however improves the crystallinity, explaining the observed spectral broadening and is also resulting in a higher mobility of the holes in P3HT. 相似文献
97.
Sabine Bertho Ilse Haeldermans Ann Swinnen Wouter Moons Tom Martens Laurence Lutsen Dirk Vanderzande Jean Manca Alessia Senes Annalisa Bonfiglio 《Solar Energy Materials & Solar Cells》2007,91(5):385-389
A new approach is presented in order to improve the thermal stability of polymer: [6-6]-phenyl C61 butyric acid methyl ester (PCBM) bulk heterojunction solar cells. The central idea in this approach is the use of a polymer with high glass transition temperature (Tg), well above the normal operating temperatures of the devices. In this paper, a PPV-derivative with a Tg of 150 °C was used as an electron donor and the thermal stability of the obtained solar cells was compared with solar cells based on the reference material poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene] (MDMO-PPV) with a Tg of 45 °C. The use of the material with higher glass transition temperature resulted in a significant improvement of the thermal stability of the photovoltaic parameters. Furthermore, a systematic transmission electron microscope (TEM) study demonstrates that the better thermal stability of performance coincides with a more stable active layer morphology. Both improvements are attributed to the reduced free movement of the electron donor material (PCBM) within the active layer of the solar cell. 相似文献
98.
AbstractA latent heat thermal energy storage system with phase change material (PCM) is numerically studied. To enhance the heat transfer inside the system, a highly conductive metal foam is employed with ceramic nanoparticles. The latter method of enhancement leads to a new class of material called Nano-PCM. The system under investigation is a 70-L tank filled up with pure PCM or Nano-PCM and several pipes are situated where the heat transfer fluid (HTF) flows. The pipe surfaces are assumed at constant temperature above the PCM melting temperature to simulate the heat transfer from the HTF. The enthalpy-porosity theory is applied to simulate the PCM phase change, while the porous media formulation is assumed to describe the metal foam behavior. The nano-PCM is modeled with single-phase model where the properties are the weighted-average between the fluid base and the nanoparticles. The simulations are accomplished for charging-discharging process at different porosities and nanoparticle concentration. The results are given in term of average melting fraction evolution, average temperature as function of time, average stored energy. The metal foam significantly improves the heat transfer between PCM and HTF respect to the addition of nanoparticles, reducing the charging and discharging time more than one order of magnitude. 相似文献
99.
Maria Selvaggi Vito Laudadio Cataldo Dario Vincenzo Tufarelli 《Journal of the science of food and agriculture》2014,94(15):3090-3099
Sheep is the second most important dairy species after cow worldwide, and especially in the Mediterranean and Middle East regions. In some countries, the difficult environmental conditions require a peculiar adaptation and, in these contexts, sheep are able to provide higher quality protein than cattle. In the least‐developed countries, the amount of dairy sheep and ovine milk production is progressively increasing. In order to improve dairy productions, in particular those with local connotations, it is necessary to obtain in‐depth information regarding milk quality and rheological properties. The genetic polymorphisms of milk proteins are often associated with quantitative and qualitative parameters in milk and are potential candidate markers that should be included in breeding strategies similar to those already available for cattle. Due to the current and growing interest in this topic and considering the large amount of new information, the aim of this study was to review the literature on sheep milk protein polymorphisms with a particular emphasis on recent findings in order to give scientists useful support. Moreover, the effects of different protein variants on milk yield and composition are discussed. © 2014 Society of Chemical Industry 相似文献
100.
Vincenzo Liso Mads Pagh Nielsen Søren Knudsen Kær Henrik H. Mortensen 《International Journal of Hydrogen Energy》2014
Temperature changes in PEM fuel cell stacks are considerably higher during load variations and have a negative impact as they generate thermal stresses and stack degradation. Cell hydration is also of vital importance in fuel cells and it is strongly dependent on operating temperature. A combination of high temperature and reduced humidity increases the degradation rate. Stack thermal management and control are, thus, crucial issues in PEM fuel cell systems especially in automotive applications such as forklifts. 相似文献