A novel hybrid process design for efficient recovery of hydrophilic ionic liquids from dilute aqueous solutions

Ionic liquids (ILs) have received much attention in both academia and industries due to their superior performance in many applications. Efficient recovery/recycling of ILs from their dilute aqueous solutions is essential for the acceptance and implementation of many IL-based technologies by industry. In this work, a practical and cost-effective hybrid process design method that combines aqueous two-phase extraction, membrane separation, and distillation operating at their highest efficiencies is proposed for the recovery of hydrophilic ILs from dilute aqueous solutions. The application of this hybrid process design method is illustrated through case studies of recovering two hydrophilic ILs, n-butylpyridinium trifluoromethanesulfonate ([C₄Py][TfO]) (CAS number: 390423-43-5) and 1-butyl-3-methylimidazolium chloride ([C₄mIm][Cl]) (CAS number: 79917-90-1), from their dilute aqueous solutions. For the recovery of 10 wt.% [C₄Py][TfO] from aqueous solution, the hybrid process using (NH₄)₂SO₄ as the salting-out agent could reduce the total annual cost (TAC) and energy consumption by 57% and 91%, respectively, compared with the pure distillation processes. In the case of recovering 10 wt.% [C₄mIm][Cl] from aqueous solution, the reduction in TAC and energy savings of the hybrid process with salting-out agent (NH₄)₂SO₃ could reach 49% and 87%, respectively, compared with the pure distillation process. Furthermore, uncertainty analysis through Monte Carlo simulations show that the proposed hybrid process design is more robust to uncertainties in energy prices and other material (e.g., equipment and solvent) costs.     

Simulating asynchronous hardware on multiprocessor platforms: the case of AMULET1

Synchronous VLSI design is approaching a critical point, with clock distribution becoming an increasingly costly and complicated issue and power consumption rapidly emerging as a major concern. Hence, recently, there has been a resurgence of interest in asynchronous digital design techniques which promise to liberate digital design from the inherent problems of synchronous systems. This activity has revealed a need for modelling and simulation techniques suitable for the asynchronous design style. The concurrent process algebra communicating sequential processes (CSP) and its executable counterpart, occam, are increasingly advocated as particularly suitable for this purpose. This paper focuses on issues related to the execution of CSP/occam models of asynchronous hardware on multiprocessor machines, including I/O, monitoring and debugging, partition, mapping and load balancing. These issues are addressed in the context of occarm, an occam simulation model of the AMULET1 asynchronous microprocessor; however, the solutions devised are more general and may be applied to other systems too. Copyright © 2001 John Wiley & Sons, Ltd.     

Hydroformylierung mit wasser- und methanollöslichen Rhodiumcarbonyl/Phenyl-sulfonatoalkylphosphan-Katalysatorsystemen – Ein neues Konzept für die Hydroformylierung höhermolekularer Olefine

Hydroformylation with Water- and Methanol-soluble Rhodium Carbonyl/phenyl-sulfonatoalkyl-phosphine Catalyst Systems – A New Concept for the Hydroformylation of Higher Molecular Olefins The heterogenization of the homogeneous hydroformylating catalyst system enables the recovery of the catalyst from the reaction products by a simple phase separation but it is unfavourable that many advantages of the homogeneous catalysis are given up by this procedure. To avoid this drawback we used rhodium carbonyl/tert. phosphine catalyst systems soluble as good in methanol as in water for the homogeneously catalyzed hydroformylation of the olefin in methanolic solution. Only after reaction the product mixture is heterogenized by adding water forming an aqueous phase containing the catalyst system. It was shown by the hydroformylation of n-tetradecene-1 with rhodium carbonyl/phenyl-sulfonatoalkyl-phosphine catalyst systems that this new conception is very useful for the oxo reaction of high-molecular olefins.     

Infrastructure-level traffic micro-simulation for probabilistic analysis of bridge loads

In state-of-the-art building codes, the traffic loads for the design or assessment of bridges should derive from a probabilistic characterization. However, because traffic depends on the vehicle flow peculiar to the transportation infrastructure of interest, the frequency of exceedance of code-assigned loads is factually unknown. This study presents a methodology to probabilistically characterize the traffic loads on bridges based on network-level traffic micro-simulation and its application to the A56, that is, the urban highway connecting Naples’ (Italy) districts. One year of traffic simulations, in conjunction with structural modeling of the bridges featured in the infrastructure, enabled the probabilistic characterization of the traffic-induced structural demand and the determination of the bridge-specific safety margins along the highway. The results of the study and of the application to A56 ultimately show that: (i) traffic micro-simulation appears to be a suitable approach to bridge-specific structural safety assessment; (ii) structural actions deriving from code-assigned loads tend to be conservative with respect to their traffic-simulation-derived counterparts; and (iii) structural demand induced by traffic loads can vary along the same transportation infrastructure.     

Revisiting QUIC attacks: a comprehensive review on QUIC security and a hands-on study

Built on top of UDP, the recently standardized QUIC protocol primarily aims to gradually replace the TCP plus TLS plus HTTP/2 model. For instance, HTTP/3 is designed to exploit QUIC’s features, including reduced connection establishment time, multiplexing without head of line blocking, always-encrypted end-to-end security, and others. This work serves two key objectives. Initially, it offers the first to our knowledge full-fledged review on QUIC security as seen through the lens of the relevant literature so far. Second and more importantly, through extensive fuzz testing, we conduct a hands-on security evaluation against the six most popular QUIC-enabled production-grade servers. This assessment identified several effective and practical zero-day vulnerabilities, which, if exploited, can quickly overwhelm the server resources. This finding is a clear indication that the fragmented production-level implementations of this contemporary protocol are not yet mature enough. Overall, the work at hand provides the first wholemeal appraisal of QUIC security from both a literature review and empirical standpoint, and it is therefore foreseen to serve as a reference for future research in this timely area.

     

On the detection of lateral movement through supervised machine learning and an open-source tool to create turnkey datasets from Sysmon logs

Lateral movement (LM) is a principal, increasingly common, tactic in the arsenal of advanced persistent threat (APT) groups and other less or more powerful threat actors. It concerns techniques that enable a cyberattacker, after establishing a foothold, to maintain ongoing access and penetrate further into a network in quest of prized booty. This is done by moving through the infiltrated network and gaining elevated privileges using an assortment of tools. Concentrating on the MS Windows platform, this work provides the first to our knowledge holistic methodology supported by an abundance of experimental results towards the detection of LM via supervised machine learning (ML) techniques. We specifically detail feature selection, data preprocessing, and feature importance processes, and elaborate on the configuration of the ML models used. A plethora of ML techniques are assessed, including 10 base estimators, one ensemble meta-estimator, and five deep learning models. Vis-à-vis the relevant literature, and by considering a highly unbalanced dataset and a multiclass classification problem, we report superior scores in terms of the F1 and AUC metrics, 99.41% and 99.84%, respectively. Last but not least, as a side contribution, we offer a publicly available, open-source tool, which can convert Windows system monitor logs to turnkey datasets, ready to be fed into ML models.

     

Estimation of Doppler spread and signal strength in mobile communications with applications to handoff and adaptive transmission

Estimation of signal strength, a measure of channel quality, and Doppler spread which is proportional to the mobile speed, are important for handoff algorithms and optimal tuning of system parameters to changing channel conditions in adaptive transmission systems. This paper provides a survey of existing techniques for estimating the statistical parameters of the mobile channel. We discuss the current state of the art in estimation of the received signal strength, mobile velocity, and other related statistical channel parameters, illustrate their performance, and compare existing techniques. The sensitivity of these schemes to modeling error owing to the presence of line of sight, directional reception, and noise is characterized analytically and illustrated by simulations. Copyright © 2001 John Wiley & Sons, Ltd.