Data Intermixing and Multi-volume Rendering

The main difference between multi-volume rendering and mono-volume rendering is data intermixing. In this paper, we present three levels of data intermixing and their rendering pipelines in direct multi-volume rendering, which discriminate image level intensity intermixing, accumulation level opacity intermixing, and illumination model level parameter intermixing. In the context of radiotherapy treatment planning, different data intermixing methods are applied to three volumes, including CT volume, Dose volume, and Segmentation volume, to compare the features of different data intermixing methods.     

Residual signal feature extraction for gearbox planetary stage fault detection

Faults in planetary gears and related bearings, e.g. planet bearings and planet carrier bearings, pose inherent difficulties on their accurate and consistent detection associated mainly to the low energy in slow rotating stages and the operating complexity of planetary gearboxes. In this work, statistical features measuring the signal energy and Gaussianity are calculated from the residual signals between each pair from the first to the fifth tooth mesh frequency of the meshing process in a multi‐stage wind turbine gearbox. The suggested algorithm includes resampling from time to angular domain, identification of the expected spectral signature for proper residual signal calculation and filtering of any frequency component not related to the planetary stage. Two field cases of planet carrier bearing defect and planet wheel spalling are presented and discussed, showing the efficiency of the followed approach and the possibility of characterizing a fault as localized or distributed. Copyright © 2017 John Wiley & Sons, Ltd.     

Preparation of Antimicrobial Coatings from Cross-Linked Copolymers Containing Quaternary Dodecyl-Ammonium Compounds

One of the concerns today’s societies face is the development of resistant pathogenic microorganisms. The need to tackle this problem has driven the development of innovative antimicrobial materials capable of killing or inhibiting the growth of microorganisms. The present study investigates the dependence of the antimicrobial activity and solubility properties on the hydrophilicity/hydrophobicity ratio of antimicrobial coatings based on quaternary ammonium compounds. In this line, suitable hydrophilic and hydrophobic structural units were selected for synthesizing the antimicrobial copolymers poly(4-vinylbenzyl dimethyldodecylammonium chloride-co-acrylic acid), P(VBCDDA-co-AA20) and poly(dodecyltrimethylammonium 4-styrene sulfonate-co-glycidyl methacrylate), P(SSAmC₁₂-co-GMA20), bearing an alkyl chain of 12 carbons either through covalent bonding or through electrostatic interaction. The cross-linking reaction of the carboxylic group of acrylic acid (AA) with the epoxide group of glycidyl methacrylate (GMA) of these two series of reactive antimicrobial copolymers was explored in blends, obtained through solution casting after curing at various temperatures. The release of the final products in pure water and NaCl 1 M solutions (as analyzed by gravimetry and total organic carbon, TOC/total nitrogen, TN analyses), could be controlled by the coating composition. The cross-linked polymeric membranes of composition 60/40 w/w % ratios led to 97.8 and 99.7% mortality for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively, whereas the coating 20/80 w/w % resulted in 96.6 and 99.8% cell reduction. Despite the decrease in hydrophobicity (from a 16- to a 12-carbon alkyl chain), the new materials maintained the killing efficacy, while at the same time resulting in increased release to the aqueous solution.     

On the importance of total polar phenols to monitor the stability of Greek virgin olive oil

A large number of virgin olive oil samples obtained from different areas in Greece were analyzed for various quality parameters. The work focuses on the colorimetric determination of total phenols with the Folin‐Ciocalteu reagent and its importance in predicting shelf life of virgin olive oil. The results indicate a good correlation of total polar phenol content with the stability of the oil. Colorimetric determination of ortho‐diphenol content does not seem to be a better means for predicting virgin olive oil stability. RP‐HPLC quantification of hydroxytyrosol and tyrosol in their free form gives poor results in the case of freshly extracted oils. It is concluded that until an easy‐to‐manage HPLC method will be available, which will quantify accurately both free and bound forms of hydroxytyrosol and other phenolics, the colorimetric method for the determination of total polar phenols remains a good practical means to evaluate the stability of virgin olive oil.     

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.     

Herstellung von hydrolysestabilen Ammoniumsalzen sulfonierter Phosphite und deren Einsatz als Cokatalysatoren in der rhodiumkatalysierten Hydroformylierung

Hydrolytic Stable Ammonium Salts of Sulfonated Organic Phosphites and their Use as Cocatalysts in the Rhodium-catalyzed Hydroformylation of Olefins Ammonium salts of sulfonated organic phosphites, which are resistant to hydrolysis, have been prepared by transesterification of triphenylphosphite with mono-ammonium salt of p-hydroxyphenylsulfonic acid in yields between 66 and 76%. A mixture containing triisooctylammonium salts of sulfonated triphenylphosphite [TPPp-SO₃HN(i-octyl)₃] was submitted to a test for stability to hydrolysis. The time required for hydrolysis of 7.4% of the TPPp-SO₃HN(i-octyl)₃ was 3 hours under drastic conditions. Triphenylphosphite was in the same test hydrolyzed quantitatively within three hours. Tetradec-1-ene was hydroformylated by means of the catalytic systems consisting of rhodium-2-ethylhexanoate with either TPPp-SO₃HN(i-octyl)₃, triphenylphosphite (TPPp) or triphenylphosphine (TPP) at 125°C, 0.6 MPa and a rhodium concentration of 50 ppm. Higher reaction selectivities for linear aldehydes were achieved with the rhodium/TPPp-SO₃HN(i-octyl)₃ catalytic system. Reaction rates increased with the Rh/TPPp-SO₃HN(i-octyl)₃ catalyst at lower temperature (110°C). Using this catalyst at 110°C, higher yields are achieved than with the Rh/TPP or Rh/TPPp catalysts. Hex-1-ene was hydroformylated by using the catalytic systems Rh₄(CO)₁₂ with TPPp-SO₃HN(i-octyl)₃, Rh₄(CO)₁₂ TPP or Rh₄ (CO)₁₂ with TPPp at 125°C, 2,5 MPa and a rhodium concentration of 20 ppm. This confirms the above experiments which indicated that higher linear: branched aldehyde ratios were obtained with the rhodium/TPPp-SO₃HN(i-octyl)₃ catalyst.     

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.