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61.
The first results of a new method for real-time shape acquisition with a laser scanner are presented. The new method is essentially based on the use of a laser beam and a web-cam. A digital filter parameters identification was studied for the laser line detection in the image. After this, a model for the reconstruction in real-time of the laser line in the space was developed. The first test rig was just conceived to validate the method; hence, no high resolution cameras were adopted. Nevertheless, the tests have showed encouraging results. 相似文献
62.
Antonella De Leonardis Giuseppe Lustrato Vincenzo Macciola Giancarlo Ranalli 《European Food Research and Technology》2010,231(4):603-610
Several chemical and physical anti-browning agents are studied in different model systems in which caffeic acid (as substrate)
and laccase from Trametes versicolor (LAC) and polyphenoloxidase from sunflower seeds (PPO) (as enzymes) are used to emulate the browning reaction. Temperature
and low electric current were the tested physical agents, while acetic acid, sodium acetate, sodium chloride and, finally,
sodium bisulfite were the chemical agents. Sunflower PPO was observed to be less heat sensitive than LAC that was fully inactivated
after 1 and 3 min of exposure to 100 and 80 °C, respectively. Conversely, PPO required more than 3 min at 100 °C to be fully
inactivated, and it still showed a significant activity (ca. 17%) after an exposure to 80 °C for 15 min. Both LAC and PPO
were found to be active at frozen (−18 °C) and cool (+4 °C) temperature, and their activities were strengthened at 40 and
60 °C. As concerning chemical agents, inhibitory power of acetic acid on LAC was observed to be very weak. In the sodium acetate
solution at the concentrations of 0.5, 1.0, 2.0 and 4.0%, LAC residual activity was equal to 81.5, 63.9, 61.1 and 35.2%, respectively.
PPO is shown to be more sensitive to the NaCl than LAC and indifferent to the presence of NaHSO3. A 28% residual activity of LAC was found in the solution with 200 mg L−1 NaHSO3. Finally, LAC activity was decreased to 72.3, 60.0, 16.7 and 8.4% after a low electric current (LEC) treatment of 30 s and
1, 3 and 6 min, respectively. Conversely, PPO activity was not affected under these conditions. 相似文献
63.
Renato Colle Giuseppe Grosso Alberto Ronzani Massimo Gazzano Vincenzo Palermo 《Carbon》2012,50(3):1332-1337
We describe the self-assembly of soluble, chemically modified fullerene [6,6]-phenyl C61 butyric acid methyl ester (PCBM) into a new crystalline phase where the C60 moieties are arranged in parallel layers. Minimum C60 center-to-center distance is 10 Å within the layers, and up to 15 Å perpendicular to the layers. Highly anisotropic, mesoscopic hexagonal crystals of this material, with a lateral size of many microns and a thickness below 1 μm, are obtained from chloroform solution by solvent vapor annealing, and characterized by optical microscopy and X-ray diffraction. The crystalline structure is deduced combining experimental data with molecular modeling and ab initio calculations. The large difference in C60–C60 spacing indicates a high anisotropy in electrical and charge transport properties of this new phase. 相似文献
64.
The objective of this work is to contribute to the recent standardisation activity, finalized to apply the Energy Performance of Buildings Directive (EPBD). Through the energy assessment of some residential buildings in Turin (Italy), the work investigates the application of the calculation methods that have been specified in the recent European standard for the so-called “standard energy rating”. A comparison of the “calculated energy rating” with the “measured energy rating” is used to investigate the effect of user behaviour and weather conditions. Moreover, in order to draft the energy certificate and make an appropriate classification, the last part of the work investigates the way to find energy reference values of the building stock, through the study of the correlation between the input and the output data of an energy rating and the comparison of the analysed buildings. 相似文献
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Analysis of interaction patterns is one of the most important indicators of quality of learning in educational web forums. Social network analysis (SNA) is gradually assuming importance in the study of interaction patterns as it focuses on the analysis of the interrelationships between individuals, thus providing a holistic perspective on group performance. However, most of the studies that use SNA in computer-supported collaborative learning scenarios derive their data from server log files, on the assumption that this data source reflects the way people really interacted online. This study, the purpose of which is to better understand the communication flows that really occur among users, challenges these assumptions through an experimental study that makes a comparison between the structural method normally used to detect the posting addressees and an approach enriched with semantic coding. Results show that this new coding schema, if compared with traditional structural coding, detected a greater number of addressees, thus allowing a greater number of postings to be included in an SNA adjacency matrix. 相似文献
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69.
Fabrizio Quadrini Loredana Santo Vincenzo Tagliaferri Federica Trovalusci 《Polymer Engineering and Science》2010,50(11):2079-2084
A new molding technique is proposed to directly mold small parts from thermoplastic pellets. A small molding machine was designed and fabricated: the mold consisted of a transparent glass and a metallic frame; an infrared (IR) lamp provided the heat for the pellet melting. Molding tests were carried out by using three commercial thermoplastics and two metallic molds. Molding time and IR lamp power were changed to extract a moldability window for each combination of material and metallic mold. In the best process conditions, a high quality of the samples was obtained in terms of mold filling and surface aesthetics. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers 相似文献
70.