Precipitation of low molecular weight phenolic compounds of grape seeds cv. Carménère (<Emphasis Type=Italic>Vitis vinifera</Emphasis> L.) by whole saliva

Low molecular weight phenolic compounds (LMWP) contribute to astringency and bitterness, two important sensory attributes. This work aimed to study the interactions between human saliva and a group of LMWP from a grape seed extract, namely, monomers, dimers and trimers of flavan-3-ol plus gallic acid. LMWP in the sediment that was produced by mixing whole saliva with the grape seed extract were identified by high-performance liquid chromatography analysis (HPLC–DAD). Two assays to produce LMWP-salivary protein sediments were carried out. An indirect assay consisted of in vitro mixing aliquots of saliva with a constant volume of the grape seed extract followed by centrifugation and sediment analysis. In a direct assay, aliquots of the grape seed extract were mixed in-mouth with saliva, returned to a vessel and centrifuged. In each assay, polyphenol composition of the sediments varied according to the tannin/saliva vol/vol ratio although in both cases monomeric LMWP were the most abundant polyphenol components of the sediments. The study also suggested the need for a strict control of the in vitro experimental conditions used to mimic the in vivo conditions in which tannin–protein interactions do occur and produce astringency perception.     

永磁直线同步电机推力波动约束

由齿槽力、边端力及法向吸力引起的推力波动是影响永磁直线同步电机(PMLSM)动态性能的主要因素。为了实现高速精密直接驱动系统,通过对PMLSM进行有限元分析建模,分析了齿槽力变化规律,利用傅里叶级数拟合得到齿槽力变化曲线;设计了齿槽力电流预测控制模型,对齿槽力引起的推力波动进行补偿;同时设计了扰动观测器对其他因素引起的推力波动进行补偿,进一步削弱了推力波动。最后,通过实验验证PMLSM推力波动补偿控制系统的有效性,补偿后电流和速度的波动都得到了很大改善,能够实现较高精度的直接驱动系统。     

Low voltage low power fully differential self‐biased 1.5‐bit quantizer with built‐in thresholds

A new fully differential self‐biased 1.5‐bit flash quantizer with built‐in threshold voltages, suitable for high speed ADCs and low voltage operation, is described. The proposed circuit is very simple, and simulation results in a 65 nm standard CMOS technology demonstrate that, following the suggested design methodology, it is able to achieve low offset, low kickback noise, low metastability probability errors and fast regeneration time with very low power dissipation. Copyright © 2011 John Wiley & Sons, Ltd.     

Cost‐Efficient Virtual Optical Network Embedding for Manageable Inter‐Data‐Center Connectivity

Network virtualization opens the door to novel infrastructure services offering connectivity and node manageability. In this letter, we focus on the cost‐efficient embedding of on‐demand virtual optical network requests for interconnecting geographically distributed data centers. We present a mixed integer linear programming formulation that introduces flexibility in the virtual‐physical node mapping to optimize the usage of the underlying physical resources. Illustrative results show that flexibility in the node mapping can reduce the number of add‐drop ports required to serve the offered demands by 40%.     

Molds and Resists Studies for Nanoimprint Lithography of Electrodes in Low-Voltage Polymer Thin-Film Transistors

A low-cost patterning of electrodes was investigated looking forward to replacing conventional photolithography for the processing of low-operating voltage polymeric thin-film transistors. Hard silicon, etched by sulfur hexafluoride and oxygen gas mixture, and flexible polydimethylsiloxane imprinting molds were studied through atomic force microscopy (AFM) and field emission gun scanning electron microscopy. The higher the concentration of oxygen in reactive ion etching, the lower the etch rate, sidewall angle, and surface roughness. A concentration around 30 % at 100 mTorr, 65 W and 70 sccm was demonstrated as adequate for submicrometric channels, presenting a reduced etch rate of 176 nm/min. Imprinting with positive photoresist AZ1518 was compared to negative SU-8 2002 by optical microscopy and AFM. Conformal results were obtained only with the last resist by hot embossing at 120 °C and 1 kgf/cm² for 2 min, followed by a 10 min post-baking at 100 °C. The patterning procedure was applied to define gold source and drain electrodes on oxide-covered substrates to produce bottom-gate bottom-contact transistors. Poly(3-hexylthiophene) (P3HT) devices were processed on high-κ titanium oxynitride (TiO _x N _y ) deposited by radiofrequency magnetron sputtering over indium tin oxide-covered glass to achieve low-voltage operation. Hole mobility on micrometric imprinted channels may approach amorphous silicon (～0.01 cm²/V s) and, since these devices operated at less than 5 V, they are not only suitable for electronic applications but also as sensors in aqueous media.     

Light and Strong SiC Networks

The directional freezing of microfiber suspensions is used to assemble highly porous (porosities ranging between 92% and 98%) SiC networks. These networks exhibit a unique hierarchical architecture in which thin layers with honeycomb‐like structure and internal strut length in the order of 1–10 μm in size are aligned with an interlayer spacing ranging between 15 and 50 μm. The resulting structures exhibit strengths (up to 3 MPa) and stiffness (up to 0.3 GPa) that are higher than aerogels of similar density and comparable to other ceramic microlattices fabricated by vapor deposition. Furthermore, this wet processing technique allows the fabrication of large‐size samples that are stable at high temperature, with acoustic impedance that can be manipulated over one order of magnitude (0.03–0.3 MRayl), electrically conductive and with very low thermal conductivity. The approach can be extended to other ceramic materials and opens new opportunities for the fabrication of ultralight structures with unique mechanical and functional properties in practical dimensions.     

CMOS harmonic upconverter with power management of $$2{\bf nd}$$ harmonic for wideband short-range communications

The design and simulation of a 2nd harmonic based upconverter is introduced. With the proposed upconverter, it is possible to reach a good noise figure with power and area reduction. The design of the circuit was made with the UMC \(0.18\,\upmu \hbox {m}\) Mixed Mode/RF CMOS technology. However, the design methodology can be extended to a different CMOS process. According to the performance exhibited by the purposed mixer, it may be useful in wideband short-range communication technologies, such as certified wireless USB.     

Quand les objets deviennent communicants La mise en confiance des acteurs humains et la question des traces numériques

The “Internet of things” is likely to give a second breath to the information society. However, the loss of control over personal information is both problematical and widely criticized. The “promise” of a better society offered by new services based on communication between machines carries with it frightening corollaries: it evokes a totalitarian space, where anonymous exchanges are no longer possible and the various traits of people’s digital identities are stored by agents of public and business powers. It is thus the management of digital tracking technologies that we wish to explore in this publication. Our hypothesis is that current criticism of a police state or of new forms of economic alienation is taking place at far too general a level. It obscures the real problem with the profusion of tracking methods, which for us reveals a crisis of confidence (as Giddens means it), at the individual level, in the means of production of telecommunications, which is the result of a deficit in the standardization process. From this perspective, the issue of the profusion of tracing technologies and their management transcends the issue of social control to encompass that of social responsibility and of modalities of proofs when the system fails.     

PNET “ONDM 2019” special issue

Photonic Network Communications -