意大利纺织机械制造商协会

<正>意大利纺织机械制造商对本届ITMA ASIA+CITME 2010的参与态度非常积极,参展商总数达到了110家,展出总面积达3900m2,其中,67家企业将加入由意     

Mechanisms and processing limits of surface finish using laser-thermochemical polishing

Laser thermochemical machining allows a controlled material removal of metallic workpieces for an aesthetic or functionalized structuring. This work deals with the question, why does a smoothing effect occurs and what are the mechanisms behind it? The results show, that the surface smoothing is based on the preferred material removal of the roughness peaks compared to the valleys, as well as microstructure related limits of the surface quality. This might be caused not by one single, but a combination of electrical, thermal and physicochemical mechanisms. These effects can be used for the controlled and selective surface polishing.     

Video transcoding from H.264/AVC to MPEG-2 with reduced computational complexity

This paper addresses video transcoding from H.264/AVC into MPEG-2 with reduced complexity and high rate-distortion efficiency. While the overall concept is based on a cascaded decoder–encoder, the novel adaptation methods developed in this work have the advantage of providing very good performance in H.264/AVC to MPEG-2 transcoding. The proposed approach exploits the similarities between the coding tools used in both standards, with the objective of obtaining a computationally efficient transcoder without penalising the signal quality. Fast and efficient methods are devised for conversion of macroblock coding modes and translation of motion information in order to compute the MPEG-2 coding format with a reduced number of operations, by reusing the corresponding data embedded in the incoming H.264/AVC coded stream. In comparison with a cascaded decoder–encoder, the fast transcoder achieves computational complexity savings up to 60% with slightly better peak signal-to-noise ratio (PSNR) at the same bitrate.     

Prediction of cooking times and weight losses during meat roasting

In this work, a meat oven cooking model is developed, and its ability to predict three main process variables – evaporative loss, dripping loss and cooking time – is evaluated. Heat transfer is modelled by Fourier’s law, while the internal moisture content variation is modelled as a function of water demand, which depends on the water holding capacity of beef. Experimental cooking of semitendinosus muscle samples was carried out in a convective oven to obtain general information about the process and to assess the model accuracy. Simulations were done by means of the finite element method, using three-dimensional irregular geometries as simulation domains. The model predictions were in good agreement with the experimental ones; the average absolute relative error was 3.91% for cooking time prediction, and 7.96% for total weight loss prediction.     

Activation of porous Ni cathodes towards hydrogen evolution by electrodeposition of Ir nuclei

Porous Ni electrodes were modified by electrodeposition of Ir nuclei from H₂IrCl₆ solutions at 70 °C, with the aim of activating them towards the hydrogen evolution reaction and comparing their performance with those of porous Ni electrodes activated by spontaneous deposition of noble metals (Ir and Ru). The current efficiency of Ir deposition was found to be very low (1% or lower, decreasing upon increasing deposition current density). Ir deposits characterised by SEM-EDX and XRD consisted of nanocrystals decorating the Ni dendrites forming the porous layers. Ir electrodeposition led to a strong activation of the hydrogen evolution reaction from aqueous 1 M NaOH. The electrocatalytic activity of the cathodes was independent of the Ir deposition charge above the minimum explored value of 1  C cm^?2. This charge is estimated to correspond to the deposition of ca. 2.5 10^?8 Ir moles cm^?2. The kinetic parameters for hydrogen evolution were similar for porous Ni electrodes modified by either spontaneous deposition (studied in a previous work) or electrodeposition of Ir.     

Does not compute — old security vs new threats

??Does not compute?? was a catchphrase in old science fiction works. It was mostly uttered by robots that were in the unfortunate situation of having to understand the human conditions in computational logic. The robots frequently exploded in such cases. IT-security finds itself in a similar situation. It has to understand a new situation: a revolutionary change in the offense. Attackers have grown up. Resourceful, strategic perpetrators have appeared on the stage. Yet IT security cannot tackle these attackers. Its?? priorities are not aligned appropriately. This suggests the need for a paradigm change. But this is not easily evoked. Persistent uncertainties hamper the necessary decisions. And unfortunately, not the inflexible IT security, but other things might explode.     

Oxygen permeation in PET bottles with passive and active walls

The aim of this paper is to provide a framework, whereby gas permeation rates through plastic packaging walls, and hence, food shelf life may be estimated. Although the approach is quite general, specific attention is given to the case of liquid‐filled polyethylene terephthalate (PET) bottles with oxygen as the permeating gas. Two situations are considered: when the walls simply provide a passive resistance to the flux (as is the case for standard PET or PET blended with some other low permeability material) and when an active gas scavenger is incorporated within the boundary material. For the passive wall, permeability data relative to oxygen have been collected from literature sources and also measured using specific oxygen transmission rate experiments. For the active walls, scavenger kinetic constants were estimated from data obtained using test bottles prepared with varying scavenger concentrations. Numerical predictions in both cases have been verified by comparison with data on gas concentration in water‐filled bottles maintained under controlled conditions for periods of up to 6 months. Copyright © 2008 John Wiley & Sons, Ltd.     

Sant'Elia's Last Project

Based on what were thought to be the only two representations of Sant'Elia's design for a military cemetery at Monfalcone, scholars believed until recently that the design was only partially executed. Two newly unearthed photographs instead affirm that the execution of the project followed Sant'Elia's plan, and they provide much fuller documentation of the project itself. The new documents also call into question the historiographic treatment of Sant'Elia in which he has chiefly been regarded a precursor of subsequent architects.