Slip in Vibrating Wire Experiments on 3He-4He Mixtures

No Heading We present vibrating wire viscometer experiments in concentrated and dilute ³He-⁴He mixtures showing that the slip length may become orders of magnitude larger than the mean free path due to increased specular scattering of the ³He quasiparticles with the superfluid ⁴He film on the wire. The experimental results are in good agreement with a recent theory for slip which accounts for the cylindrical geometry of the wire and for velocity slip in directions normal as well as tangential to the surface of the wire.PACS numbers: 67.60.Fp, 51.20.+d     

Effect of Fiber Length on Carbon Nanotube-Induced Fibrogenesis

Given their extremely small size and light weight, carbon nanotubes (CNTs) can be readily inhaled by human lungs resulting in increased rates of pulmonary disorders, particularly fibrosis. Although the fibrogenic potential of CNTs is well established, there is a lack of consensus regarding the contribution of physicochemical attributes of CNTs on the underlying fibrotic outcome. We designed an experimentally validated in vitro fibroblast culture model aimed at investigating the effect of fiber length on single-walled CNT (SWCNT)-induced pulmonary fibrosis. The fibrogenic response to short and long SWCNTs was assessed via oxidative stress generation, collagen expression and transforming growth factor-beta (TGF-β) production as potential fibrosis biomarkers. Long SWCNTs were significantly more potent than short SWCNTs in terms of reactive oxygen species (ROS) response, collagen production and TGF-β release. Furthermore, our finding on the length-dependent in vitro fibrogenic response was validated by the in vivo lung fibrosis outcome, thus supporting the predictive value of the in vitro model. Our results also demonstrated the key role of ROS in SWCNT-induced collagen expression and TGF-β activation, indicating the potential mechanisms of length-dependent SWCNT-induced fibrosis. Together, our study provides new evidence for the role of fiber length in SWCNT-induced lung fibrosis and offers a rapid cell-based assay for fibrogenicity testing of nanomaterials with the ability to predict pulmonary fibrogenic response in vivo.     

Cyclic invariance for discrete time-delay systems

This technical communique introduces a new concept of set invariance with respect to linear discrete time dynamics affected by delay. We are interested in the definition and characterization of sequences of cyclically invariant subsets in the state space. The algebraic conditions established in the late ’80s for linear dynamics are generalized to invariance analysis in the presence of delays for given sequences of polyhedral sets.     

A review of biodiesel production by integrated reactive separation technologies

Biodiesel is a biodegradable and renewable fuel, emerging as a viable alternative to petroleum diesel. Conventional biodiesel processes still suffer from problems associated with the use of homogeneous catalysts and the limitations imposed by the chemical reaction equilibrium, thus leading to severe economic and environmental penalties. This work provides a detailed review—illustrated with relevant examples—of novel reactive separation technologies used in biodiesel production: reactive distillation/absorption/extraction, and membrane reactors. Reactive separation offers new and exciting opportunities for manufacturing the fatty acid alkyl esters involved in the industrial production of biodiesel and specialty chemicals. The integration of reaction and separation into one operating unit overcomes equilibrium limitations and provides major benefits such as low capital investment and operating costs. These reactive separation processes can be further enhanced by heat‐integration and powered by heterogeneous catalysts, to eliminate all conventional catalyst related operations, using efficiently the raw materials and the reaction volume, while offering higher conversion and selectivity, as well as significant energy savings compared with conventional biodiesel processes. Remarkable, in spite of the high degree of integration, such integrated reactive‐separation processes are still very well controllable as illustrated by the included examples. Copyright © 2012 Society of Chemical Industry     

Pullulan: A versatile coating agent for superparamagnetic iron oxide nanoparticles

Ultrasmall superparamagnetic iron oxide (Fe₃O₄) nanoparticles coated by biocompatible pullulan (Pu‐USPIO) with sizes below 10 nm and having a magnetite core and a hydrophilic outer shell of pullulan were prepared. The formed Pu‐USPIOs were thoroughly characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy, and small‐angle X‐ray scattering experiments. The content of magnetic nanoparticles embedded into the pullulan matrix was determined by thermogravimetric analysis. Vibrating sample magnetometry analysis was used to evaluate the magnetic properties of the Pu‐USPIO samples. Because of the presence of pullulan, these nanoparticles could be conditioned in many versatile forms, from a clear solution to magnetic films, for potential applications, including magnetic hyperthermia mediators. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42926.     

Comparative Study of 9×19 mm Ammunition Combustion Products and Residues

During the last decades, authorities’ awareness on environmental and human health impact at national and international level has increased in the field of small arms ammunition containing lead and antimony. Thus, the evolution of environmental policies regarding production and use of heavy metals and their compounds, especially in EU countries, implied extensive studies on the environmental implications of 9×19 mm caliber ammunition use, especially in indoor shooting ranges. In this context, the paper describes the experimental studies performed on Pb‐containing conventional FMJ (full metal jacketed) ammunition and comparative measurements on new ammunition designed for training. The combustion products and residues from conventional Pb‐containing ammunition and Cu‐based “greener” ammunition were compared in terms of gaseous products, metal concentration in aerosols and metal concentrations in solid residues. Gas emissions and solid residues were measured for four different types of ammunitions. The results showed that the copper content of the residue is significantly higher in case of Cu‐containing composite bullets. For the ammunition equipped with Pb bullet, an important percentage of the Pb residue is generated by erosion of the exposed part of the bullet core. On the other hand, the ammunition containing Cu‐composite bullet generates large quantities of Cu residues, which have similar environmental impact and less impact on human health. Gas analysis indicated the presence of CO and NO_x and, surprisingly, high concentrations of HCN, CH₄, and NH₃. Lower gas concentrations are obtained for the composite bullets due to an incomplete combustion of gun propellant.     

Multistage access network for bidirectional DWDM transmission using ASE-injected FP-LD

We propose a novel optical distribution network for multistage optical access network with multiple remote nodes (RNs) using 4skip0 filters. The system can be implemented by use of 1/spl times/N arrayed waveguide grating in the central office, cascaded RNs, and a plurality of optical network units (ONUs). It also employs colorless ONUs based on incoherent light injected Fabry-Pe/spl acute/rot laser diodes for low operation and maintenance cost. Experiment shows error-free transmission with simultaneous bidirectional 1.25 Gb/s per channel up to 20 km.     

The meta-stable dip (MSD) effect in SOI FinFETs

The meta-stable dip (MSD) effect is demonstrated and characterized in SOI FinFETs. With ascending scan of front-gate voltage (V_G1), the magnitude of drain current (I_D) tends to be fixed within a specific region of the front-gate voltage and this leads to a dip of transconductance (g_m). The dip width can be modulated through a control of bias condition or measurement speed such as back-gate voltage (V_G2), drain voltage (V_D) and step size of the front-gate voltage. From the dual-gate transient measurement, it is found that the MSD effect is highly dependent on the floating-body effect. In SOI FinFETs, the MSD effect is significantly affected by the fin width due to the fringing electric field of the lateral gates.     

Generic fitted shapes (GFS): Volumetric object segmentation in service robotics

In this paper, a simultaneous 3D volumetric segmentation and reconstruction method, based on the so-called Generic Fitted Shapes (GFS) is proposed. The aim of this work is to cope with the lack of volumetric information encountered in visually controlled mobile manipulation systems equipped with stereo or RGB-D cameras. Instead of using primitive volumes, such as cuboids or cylinders, for approximating objects in point clouds, their volumetric structure has been estimated based on fitted generic shapes. The proposed GFSs can capture the shapes of a broad range of object classes without the need of large a-priori shape databases. The fitting algorithm, which aims at determining the particular geometry of each object of interest, is based on a modified version of the active contours approach extended to the 3D Cartesian space. The proposed volumetric segmentation system produces comprehensive closed object surfaces which can be further used in mobile manipulation scenarios. Within the experimental setup, the proposed technique has been evaluated against two state-of-the-art methods, namely superquadrics and 3D Object Retrieval (3DOR) engines.