Search results for "Note"
showing 10 items of 10709 documents
Modular approach to microswimming
2018
The field of active matter in general and microswimming in particular has experienced a rapid and ongoing expansion over the last decade. A particular interesting aspect is provided by artificial autonomous microswimmers constructed from individual active and inactive functional components into self-propelling complexes. Such modular microswimmers may exhibit directed motion not seen for each individual component. In this review, we focus on the establishment and recent developments in the modular approach to microswimming. We introduce the bound and dynamic prototypes, show mechanisms and types of modular swimming and discuss approaches to control the direction and speed of modular microsw…
A comparative molecular dynamics-phase-field modeling approach to brittle fracture
2016
Abstract In this work, a novel comparative method for highly brittle materials such as aragonite crystals is proposed, which provides an efficient and accurate in-sight understanding for multi-scale fracture modeling. In particular, physically-motivated molecular dynamics (MD) simulations are performed to model quasi-static brittle crack propagation on the nano-scale and followingly compared to macroscopic modeling of fracture using the phase-field modeling (PFM) technique. A link between the two modeling schemes is later proposed by deriving PFM parameters from the MD atomistic simulations. Thus, in this combined approach, MD simulations provide a more realistic meaning and physical estima…
Efficient mesoscale hydrodynamics: Multiparticle collision dynamics with massively parallel GPU acceleration
2018
Abstract We present an efficient open-source implementation of the multiparticle collision dynamics (MPCD) algorithm that scales to run on hundreds of graphics processing units (GPUs). We especially focus on optimizations for modern GPU architectures and communication patterns between multiple GPUs. We show that a mixed-precision computing model can improve performance compared to a fully double-precision model while still providing good numerical accuracy. We report weak and strong scaling benchmarks of a reference MPCD solvent and a benchmark of a polymer solution with research-relevant interactions and system size. Our MPCD software enables simulations of mesoscale hydrodynamics at lengt…
Flexible design of multifocal metalenses based on autofocused Airy beams
2018
Extreme miniaturization of on-demand optical devices such as ultrathin lenses is currently leading to significant advancements in manufacturing novel materials and nanotechnologies. Flexibility and tunability of engineered layouts enable efficient integration of complex photonic modules. In this regard, here we propose an autofocused Airy (AFA)-based metalens that operates, depending on the molded phase profile, as a multifocal focusing lens, which to the best of our knowledge has not been reported before. To do this, we call attention to the fact that the two conjugate focal points of an AFA beam can be brought into real space by applying a proper convex lens phase profile. Considering ful…
Design, realization, and testing of a SPR biosensing system for wine quality monitoring
2007
A complete innovative and portable, for on-field operation, Surface Plasmon Resonance (SPR) biosensing system for wine quality monitoring was designed, realized and tested; the system takes advantage of the innovative module Spreeta™, an integrated transducer designed by Texas Instruments able to recognize the Surface Resonance Phenomena and to represent it through electrical signals. The system, based on an 8 bit microprocessor board, acquires through a 12 bit A/D converter, elaborates and sends to a PC data from the Spreeta™ sensor. A proprietary high-level software calculates the refractive index related to biological solution flowing on the surface sensor and lets to detect suitable sub…
A feasibility analysis on the use of ultrasonic multihop communications for E-health applications
2017
Rise in population aging as well as diffusion of chronic diseases and health consciousness require constant monitoring of health conditions but also lead to increasing costs for the governments. Body Area Networks represent the next frontier in health care and are envisaged as the natural choice to provide detailed and updated information on health status to prevent health risks and diseases. However if, on the one hand, a large research effort has been devoted so far to the investigation of BAN communications on and around the body, on the other hand intra-BAN communications are still a scarcely explored area because of the difficulties and risks in successfully propagating signals inside …
Non-invasive analysis of solid samples
2013
Within the Green Analytical Chemistry paradigm, the best alternative for greening the methods of analysis comprises the direct determination of sample composition and/or sample properties without any chemical sample treatment, and, of course, it would be preferable not to have any physical treatment before acquisition of the information desired. In this review, we evaluate the state of the art in, and available alternatives for, analysis of solids without prior sample treatment, starting from the non-invasive quality control of products or processes through to the use of portable instruments for in situ determinations and the development of methods based on image analysis. We evaluate the a…
Assessment of a pilot system for seawater desalination based on vacuum multi-effect membrane distillation with enhanced heat recovery
2018
Abstract This work presents the evaluation of an innovative system based on vacuum multi-effect membrane distillation modules (V-MEMD) for seawater desalination at pilot scale. This four-effect unit introduces a remarkable modification from previous V-MEMD systems, consisting of the use of the seawater feed flow as cooling in the condenser, rather than a separate circuit. Preheating the feed in the condenser improved heat efficiency (maximum gained output ratio obtained for seawater was 3.2). Maximum distillate fluxes reached 8.5 l h−1 m−2 for hot feed temperature 75 °C and feed flow rate 150 l h−1. Increasing both parameters to raise the productivity was hindered by the inability of the co…