Study of mass transfer and determination of drop size distribution in a pulsed extraction column

A better understanding of pulsed liquid-liquid extraction columns was obtained by using an online digital image analysis system to characterize emulsion drop. The mass transfer of acetic acid from dispersed phase (ethyl acetate) to continuous phase (water) was studied under standard conditions. The system enabled drop size distribution (DSD) to be measured as a function of physical and thermodynamic parameters. The surface tension was investigated by static contact angle measurement. Mass transfer and energy transfer, characterized by the surface/volume ratio of the droplets were compared with the working parameters in order to interpret restrictive phenomena such as hold up and column efficiency. The experimental values of Sauter diameter (d₃₂) and those predicted by a correlation proposed in the literature are in good agreement. However, the adhesion work between liquid and PTFE plate surface indicates that interface property variations, as a function of solute concentration, must be taken into account in the theoretical correlations. It was found that hold up and separation efficiency depend mainly on the stirring rate. These results show that online image analysis can be used as a process control of a liquid-liquid extraction column in order to optimize the mixing phenomena and the DSD, the key parameter of extraction efficiency.     

Path similarity evaluation using Bloom filters

The performance of several Internet applications often relies on the measurability of path similarity between different participants. In particular, the performance of content distribution networks mainly relies on the awareness of content sources topology information. It is commonly admitted nowadays that, in order to ensure either path redundancy or efficient content replication, topological similarities between sources is evaluated by exchanging raw traceroute data, and by a hop by hop comparison of the IP topology observed from the sources to the several hundred or thousands of destinations.In this paper, based on real data we collected, we advocate that path similarity comparisons between different Internet entities can be much simplified using lossy coding techniques, such as Bloom filters, to exchange compressed topology information. The technique we introduce to evaluate path similarity enforces both scalability and data confidentiality while maintaining a high level of accuracy. In addition, we demonstrate that our technique is scalable as it requires a small amount of active probing and is not targets dependent.     

Depth resolution and multiexponential lifetime analyses of reflectance-based time-domain fluorescence data

Time-domain fluorescence imaging is a powerful new technique that adds a rich amount of information to conventional fluorescence imaging. Specifically, time-domain fluorescence can be used to remove autofluorescence from signals, resolve multiple fluorophore concentrations, provide information about tissue microenvironments, and, for reflectance-based imaging systems, resolve inclusion depth. The present study provides the theory behind an improved method of analyzing reflectance-based time-domain data that is capable of accurately recovering mixed concentration ratios of multiple fluorescent agents while also recovering the depth of the inclusion. The utility of the approach was demonstrated in a number of simulations and in tissuelike phantom experiments using a short source-detector separation system. The major findings of this study were (1) both depth of an inclusion and accurate ratios of two-fluorophore concentrations can be recovered accurately up to depths of approximately 1 cm with only the optical properties of the medium as prior knowledge, (2) resolving the depth and accounting for the dispersion effects on fluorescent lifetimes is crucial to the accuracy of recovered ratios, and (3) ratios of three-fluorophore concentrations can be resolved at depth but only if the lifetimes of the three fluorophores are used as prior knowledge. By accurately resolving the concentration ratios of two to three fluorophores, it may be possible to remove autofluorescence or carry out quantitative techniques, such as reference tracer kinetic modeling or ratiometric approaches, to determine receptor binding or microenvironment parameters in point-based time-domain fluorescence applications.     

An optimized and power savings protocol for mobility energy-aware in wireless sensor networks

Mobility management in Wireless Sensor Networks (WSNs) is a complex problem that must be taken into account in all layers of the protocol stack. But this mobility becomes very challenging at the MAC level in order to do not degrade the energy efficiency between sensor nodes that are in communication. However, among medium access protocols, sampling protocols reflect better the dynamics of such scenarios. Nevertheless, the main problem, of such protocols, remains the management of collisions and idle listening between nodes. Previous approaches like B-MAC and X-MAC, based on sampling protocols present some shortcomings. Therefore, we address the mobility issue of WSNs that use as medium access sampling protocols. Firstly, we propose a mobile access solution based on the X-MAC protocol which remains a reference protocol. This protocol, called MoX-MAC, incorporates different mechanisms that enables to mitigate the energy consumption of mobile sensor nodes. Furthermore, we extend our former work (Ba et al. in Proc. of IEEE WMNC, 2011) by evaluating the lifetime of static nodes with respect to MoX-MAC protocol, as well determine the degree of depletion of static nodes due to the presence of mobile nodes.     

Constraint-Based Geolocation of Internet Hosts

Geolocation of Internet hosts enables a new class of location-aware applications. Previous measurement-based approaches use reference hosts, called landmarks, with a well-known geographic location to provide the location estimation of a target host. This leads to a discrete space of answers, limiting the number of possible location estimates to the number of adopted landmarks. In contrast, we propose Constraint-Based Geolocation (CBG), which infers the geographic location of Internet hosts using multilateration with distance constraints to establish a continuous space of answers instead of a discrete one. However, to use multilateration in the Internet, the geographic distances from the landmarks to the target host have to be estimated based on delay measurements between these hosts. This is a challenging problem because the relationship between network delay and geographic distance in the Internet is perturbed by many factors, including queueing delays and the absence of great-circle paths between hosts. CBG accurately transforms delay measurements to geographic distance constraints, and then uses multilateration to infer the geolocation of the target host. Our experimental results show that CBG outperforms previous geolocation techniques. Moreover, in contrast to previous approaches, our method is able to assign a confidence region to each given location estimate. This allows a location-aware application to assess whether the location estimate is sufficiently accurate for its needs     

Novel nanostructured pHEMA-TiO2 hybrid materials with efficient light-induced charge separation

We report on a new approach to the fabrication of an electronic material: organic-inorganic pHEMA-oxo-TiO(2) hybrid with efficient light-induced separation of charges. Particular attention is paid to the material nanoscale morphology. The size-selected 5.0 nm titanium oxo-alkoxy nanoparticles are prepared in a sol-gel reactor with rapid (turbulent) fluid micromixing and the ligand exchange results in a stable nanoparticulate precursor in HEMA solution, in which polymerization can be induced thermally or by photons. The obtained hybrid materials demonstrate the highest quantum yield of photoinduced charge separation of 50% and can store photoinduced electrons at a number density above 10% Ti atoms.     

I4EU (Industry 4.0 for European Union) ——An European Initiative to Develop Training Activity

This paper presents an on-going European ERASMUS project to develop training programs and tools for Industry 4.0. After an introduction on the background and objective of the project, the paper will give an overview on the structure, partners and organization of the project. Based on the State-of-the-art, the targeted intellectual outputs (IOs) will be presented in detail and the set of planned activities to achieve IOs are outlined. The project progress and preliminary results are shown and the concluding summary will be given at the end of the paper.     

The State of the Art in Agent Communication Languages

Like societies of humans, there is a need for agents in a multi-agent system to rely on one another, enlist the support of peers in order to solve complex tasks. Agents will be able to cooperate only through a meaningful communication language that can bear correctly their mental states and convey precisely the content of their messages. In search for the ideal agent communication language (ACL), several initiatives like the pioneering work of the Knowledge Sharing Effort and the Foundation for Intelligent Physical Agents (FIPA) are paving the way for a platform where all agents would be able to interact regardless of their implementation environment. ACL is a new field of study that could gain from a survey in expanding its application areas. For this purpose, we examine in this paper the state of the art in ACL design and suggest some principles for building a generalized ACL framework. We then evaluate some existing ACL models, and present the current issues in ACL research, and new perspectives. Received 22 July 1999 / Revised 23 March 2000 / Accepted 2 May 2000