Controllable Image‐Based Transfer of Flow Phenomena

Modelling flow phenomena and their related weathering effects is often cumbersome due their dependence on the environment, materials and geometric properties of objects in the scene. Example‐based modelling provides many advantages for reproducing real textures, but little effort has been devoted to reproducing and transferring complex phenomena. In order to produce realistic flow effects, it is possible to take advantage of the widespread availability of flow images on the Internet, which can be used to gather key information about the flow. In this paper, we present a technique that allows the transfer of flow phenomena between photographs, adapting the flow to the target image and giving the user flexibility and control through specifically tailored parameters. This is done through two types of control curves: a fitted theoretical curve to control the mass of deposited material, and an extended colour map for properly adapting to the target appearance. In addition, our method filters and warps the input flow in order to account for the geometric details of the target surface. This leads to a fast and intuitive approach to easily transfer phenomena between images, providing a set of simple and intuitive parameters to control the process.     

Development of UV-curable ZrO2 slurries for additive manufacturing (LCM-DLP) technology

Digital Light Processing (DLP) is a powerful technique for the preparation of ceramic parts with high resolution and complex shapes. In the last years, the development of photosensitive slurries for the production of ceramics with good mechanical properties has received much attention. In this work, ZrO₂ UV-curable slurries were prepared in two steps for their application in DLP. Firstly, the surface modification of the ZrO₂ particles was carried out using a dispersing agent and secondly, the modified powder was dispersed in an acrylate based mixture. Parts with different geometries were printed and a resolution experiment was also carried out in order to determine the limitations of the slurry. Finally, 30 bars were produced to study the mechanical properties of the sintered parts (ρ = 6.00 ± 0.01 g/mL) by 4-point bending tests and Weibull analysis, obtaining a flexural strength σ₀ = 741 (718–765) MPa with a Weibull coefficient of 11.4.     

大规模MIMO系统上行链路时间-空间结构信道估计算法

针对大规模多入多出(MIMO)系统上行链路非平稳空间相关信道的估计问题,该文利用信道的时间-空间2维稀疏结构信息,应用狄利克雷过程(DP)和变分贝叶斯推理(VBI),设计了一种低导频开销和计算复杂度的信道估计迭代算法,提高了信道估计精度。由于平稳空间相关信道难以适用于大规模MIMO系统,该文借助于狄利克雷过程构建了非平稳空间相关信道先验模型,可将具有空间关联的多个物理信道映射为具有相同时延结构的概率信道,并应用变分贝叶斯推理设计了低导频开销和计算复杂度的信道估计迭代算法。实验结果验证了所提算法的有效性,且具有对系统关键参数鲁棒性的优点。     

Kinetics of the liquid phase dehydration of 1‐octanol to di‐n‐octyl ether on Amberlyst 70

The kinetics of the liquid phase dehydration of 1‐octanol to di‐n‐octyl ether (DNOE) over Amberlyst 70 was studied at 413–453 K. Mechanistic rate models assuming water and 1‐octanol adsorbed on the resin, and the free sites fraction negligible, were selected from 1‐octanol dehydration experiments. Next, the influence of DNOE, water, and 1,4‐dioxane (solvent) concentration was evaluated. DNOE and 1,4‐dioxane do not affect significantly the reaction rate, while water inhibits it strongly. Water effect was quantified by splitting the rate constant into a “true one” and a correction factor related to the fraction of active sites blocked by water. The best kinetic model stemmed from an Eley‐Rideal mechanism with water adsorbed onto the resin and DNOE released directly to the liquid phase, with a correction factor for water inhibitory effect based on a Freundlich isotherm‐like function; activation energy being 110 ± 5 kJ·mol^?1, in line with literature data on homologous reactions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3966–3978, 2017     

An iron-based T 1 contrast agent made of iron-phosphate complexes: In vitro and in vivo studies

A new iron-based T ₁ contrast agent consisting of a complex of iron ions coordinated to phosphate and amine ligands (Fe_(phos) in short) has been characterized by spectroscopic and magnetic measurements. NMR relaxation studies showed r ₁ values to be dependent on the phosphate salt concentration, K₂HPO₄, present in the medium. r ₁ reaches a maximum value of 2.5 mM^?1 s^?1 for measurements carried out at 7 T and 298 K. ³¹P MRS, Mössbauer spectroscopy and magnetic measurements of Fe_(phos) solutions suggest paramagnetic Fe³⁺ ions present in the studied iron–phosphate complex. In vitro and in vivo toxicity experiments with C6 cells and CD1 mice, respectively, demonstrated lack of toxicity for Fe_(phos) at the highest dose tested in the MRI experiments (12 mM iron for C6 cells and 0.32 mmol iron/kg for mice). Finally, T ₁ weighted images of brain tumours in mice have shown positive contrast enhancement of Fe_(phos) for tumour afflicted regions in the brain.     

Sound influence on landscape values

In order to study the influence of the interaction between visual and acoustic stimuli on perception of the environment, 36 sound and image combinations were presented to 75 subjects. The sounds and images used were of natural and semi-natural settings and urban green space. Affective response was measured in terms of pleasure. The results show a rank of preferences running from natural to man-made sounds, with the nuance of a potential alert or alarm-raising component of the sound. The potential for alert or alarm-raising may be related, over and above the information content or meaning, to the characteristics of the sound frequency spectrum, specifically to the existence of frequency bands whose sound levels impose themselves on the acoustic background. The congruence or coherence between sound and image influences preferences. Coherent combinations are rated higher than the mean of the component stimuli. Results suggest that there is a need to identify places or settings where the conservation of the sound environment is essential, because of its salient informational content or due to the drastic impact of the loss of sound quality on observer appreciation, for example, in urban green spaces, natural spaces and cultural landscapes.     

Lipase‐catalysed synthesis of natural ethanol esters: effect of water removal on enzyme reutilisation

Lipase‐catalysed synthesis of ethanol esters using natural substrates is presented. Initial substrate concentrations, optimised through an experimental design, were 0.8 mol dm⁻³ lauric acid and 0.58 mol dm⁻³ ethanol, with an initial esterification rate (r₀) of 17.13 mmol dm⁻³ min⁻¹. Two different water removal systems were compared: a cooling exchanger in the reactor headspace and a vacuum‐based system. The best results were obtained with the second system. After six consecutive operations with the same enzyme, no loss of activity was observed. The yields obtained in all the runs were greater than 90%. Using the same approach three different natural esters (ethyl laureate, ethyl myristate and ethyl palmitate) were synthesised at 0.9 dm³ scale. Similar results were obtained in all three cases, with chemical yields always being greater than 90%. © 2000 Society of Chemical Industry     

Adhesion of Ceramic Coating on Thin and Smooth Metal Substrate: A Novel Approach with a Nanostructured Ceramic Interlayer

The adhesion of plasma-sprayed coating is, to a large extent, controlled by the cleanness and roughness of the surface on which the coating is deposited. So, most of the plasma spray procedures involve surface pretreatment by grit-blasting to adapt the roughness of the surface to the size of the impacting particles. This preparation process brings about compressive stresses that make it inappropriate for thin substrates. The present works aim to elaborate a thick ceramic coating (about 0.5?mm thick) on a thin metal substrate (1?mm thick) with a smooth surface (Ra of about 0.4???m). The coating system is intended for use in a Generation-IV nuclear energy system. It must exhibit a good adhesion between the ceramic topcoat and the smooth metal substrate to meet the specifications of the application. Our approach consisted of depositing the ceramic topcoat by air plasma spraying on a few micrometers thick ceramic layer made by suspension plasma spraying. This nanostructured layer played the role of a bond coat for the topcoat and made it possible to deposit it on the as-received substrate. The adhesion of the nanostructured layer was measured by the Vickers indentation cracking technique and that of the ceramic duplex coating system by tensile test.