Synthesis and characterization of eugenol-based silicone modified waterborne polyurethane with excellent properties

A eugenol-based silicone-containing monomer 4,4′-(1,1,3,3-tetramethyldisiloxane-1,3-dipropyl)bis-2-methoxyphenol(EUSi) was synthesized from eugenol and 1,1,3,3-tetramethyldisiloxane via the hydrosilylation reaction. And waterborne polyurethane (WPU) with excellent properties was obtained by using EUSi as a type of diol chain extender. The unique combination of rigidity and flexibility in the chemical structure of EUSi greatly facilitated the mechanical properties, thermal properties, and water resistance of WPU. With only a 3% dosage of EUSi, the maximum tensile strength was increased from 6.2 to 22.4 MPa, while the water absorption was decreased from 31.3% to a surprisingly 7.6%. Our work provides a new convenient strategy for the preparation of organosilicon-modified WPU with improved performance.     

Monitoring the curing processes of epoxy oligomers with partially substituted polyethoxymetallosiloxanes by IR spectroscopy and thermomechanical analysis

In this work, the curing of «ED-20» epoxy resin with partially siloxy-substituted aluminum, iron, and zirconium siloxanes that we obtained previously was studied. The initial content of a metallosiloxane in the compositions was 5–50 wt% with respect to the resin. In all the cases, thermal curing was used to obtain a series of samples in the form of solid homogeneous materials. The fact of the epoxy ring opening in the resin was confirmed by IR spectroscopy. The catalytic properties of the metal atom in a metallosiloxane were found to affect the curing process. The samples demonstrate rather a high resistance to thermooxidative destruction, and in most cases, their glass transition temperatures are lower than those obtained upon standard curing of «ED-20» resin with triethylenetetramine. Partially siloxy-substituted metalloalkoxysiloxanes can be efficient agents for curing and formation of a hybrid material based on epoxy resins.     

Poly(N-methylaniline) coatings on stainless steel by electropolymerization

Poly(N-methylaniline) (PNMA) coatings have been electropolymerized on 304 stainless steel alloy by potentiodynamic, galvanostatic and potentiostatic synthesis techniques from aqueous solutions of 0.1 M N-methylaniline (NMA) and 0.3 M oxalic acid. Characterization of PNMA coatings was carried out by cyclic voltammetry, UV-Vis and FTIR spectroscopy techniques. Corrosion behavior of PNMA coated stainless steel electrodes was investigated using linear anodic potentiodynamic polarization, Tafel test, chronoamperometry and electrochemical impedance spectroscopy (EIS) techniques in 0.5 M aqueous HCl solutions. Corrosion test results showed that PNMA coatings possessed protection to uncoated stainless steel against corrosion.     

Modelling Fine-Grained Access Control Policies in Grids

This paper presents an abstract specification of an enforcement mechanism of usage control for Grids, and verifies formally that such mechanism enforces UCON policies. Our technique is based on KAOS, a goal-oriented requirements engineering methodology with a formal LTL-based language and semantics. KAOS is used in a bottom-up form. We abstract the specification of the enforcement mechanism from current implementations of usage control for Grids. The result of this process is agent and operation models that describe the main components and operations of the enforcement mechanism. KAOS is used in top-down form by applying goal-refinement in order to refine UCON policies. The result of this process is a goal-refinement tree, which shows how a goal (policy) can be decomposed into sub-goals. Verification that a policy can be enforced is then equivalent to prove that a goal can be implemented by the enforcement mechanism represented by the agent and operation models.     

Interference impacts on 60 ghz real-time online video streaming in wireless smart tv platforms

In this paper we provide a method for computing and estimating the impact of interference on real-time online 1080p@30Hz and 1080p@60Hz high-definition video streaming in 60 GHz wireless smart TV platforms. The analysis involves two different interference scenarios: 1) downlink interference from deployed 60 GHz access points to the associated mobile ad-hoc devices, and 2) uplink interference from randomly deployed 60 GHz ad-hoc mobile devices to their associated access points. With these interference scenarios, the interference impact on the quality of main 1080p@30Hz and 1080p@60Hz wireless high-definition video streaming with various simulation settings are measured and estimated in terms of signal-to-interference-plus-noise ratio.     

Multiple responses analysis and modeling of Fenton process for treatment of high strength landfill leachate

Landfill leachate is one of the most recalcitrant wastes for biotreatment and can be considered a potential source of contamination to surface and groundwater ecosystems. In the present study, Fenton oxidation was employed for degradation of stabilized landfill leachate. Response surface methodology was applied to analyze, model and optimize the process parameters, i.e. pH and reaction time as well as the initial concentrations of hydrogen peroxide and ferrous ion. Analysis of variance showed that good coefficients of determination were obtained (R2 > 0.99), thus ensuring satisfactory agreement of the second-order regression model with the experimental data. The results indicated that, pH and its quadratic effects were the main factors influencing Fenton oxidation. Furthermore, antagonistic effects between pH and other variables were observed. The optimum H2O2 concentration, Fe(II) concentration, pH and reaction time were 0.033 mol/L, 0.011 mol/L, 3 and 145 min, respectively, with 58.3% COD, 79.0% color and 82.1% iron removals.     

Low-power high-speed interconnection networks in NOC using multi-valued current-mode techniques

With the fast developments and growth of electronic applications and a great demand for increasing the speed of processors, VLSI circuits and on-chip interconnections the ＂Networks-On-Chip＂ （NOC） is the best solution for ＂System-On-Chip＂ （SOC）. The most fundamental part of networks On-Chip is the On-Chip interconnection. The model presented in this article describes the method of sending data on On-Chip interconnection by using a current-mode multi-valued logic instead of voltage-mode in order to increase speed and reduce the number of interconnection wires.     

Comparative effects of gamma and microwave irradiation on the quality of black pepper

Powdered black pepper from Egyptian markets, was irradiated with different recommended doses of gamma rays (5.0 and 10.0 kGy) and with microwaves for different periods (20, 40 and 75 s) to improve its hygienic quality. The most common bacterial isolates were of three generaBacillus, Clostridium andMicrococcus (7.5 × 10⁶), whereas the predominant fungi (7.8 × 10⁴) wereAspergillus species,A. glaucus, A. flavus, A. niger andA. ochraceus. Doses of gamma irradiation used (5.0 and 10 kGy) were sufficient to decrease spore-forming bacteria (SFB) and to inhibit the fungal flora and coliforms which contaminated the black pepper powder. Microwave treatments for 40 s and 75 s were of the same effectiveness whereas treatment for 20 s was less so. GLC analysis proved the presence of 31 peaks, only 19 compounds were identified as monoterpene hydrocarbons (56.21%), the major one being -phellandrene and limonene. Sesquiterpenes were also present, mainly -caryollphyllene (3.69%) as well as oxygenated compounds such as terpenol, geraniol, Me-chavicol, eugenol and anisol. Gamma irradiation at 5 kGy and 10 kGy respectively decreased the numbers of identified compounds from 21 (86.58% concentration) in untreated pepper to 16 (59.22% concentration), 15 (54.06% concentration). In comparison, microwave treatments, particularly for 40 s and 75 s, increased the concentration of the same compounds. The results obtained indicate that microwave treatment, under these conditions, is a safe and suitable technique for decontamination of black pepper which does not result in a great loss of flavour compounds, as compared with recommended doses of gamma irradiation.     

Novel method to transform ZnO nanorods into interlaced tattered nanosheets by changing the target inclination angle

ZnO nanoparticles were synthesized by liquid-phase pulse laser ablation of a Zn foil target immersed in deionized water. Nanosecond Q-switched Nd:YAG laser pulses of 532 nm were applied to the Zn foil target at a perpendicular and inclined (θ = 45°) angles. X-ray diffraction analysis revealed that both cases feature a ZnO nanostructure with a hexagonal wurtzite structure and that the particle size increases with the inclined target angle. Field emission scanning electron microscopy results of a colloidal drop cast on a glass substrate showed the ZnO has a nanorod structure in the case of a perpendicular target angle and an interlaced tattered nanosheet structure in the case of an inclined target angle. Photoluminescence spectra showed emission peaks in the UV, violet, blue, and green spectral regions, which correspond to excitonic and various defects resulting in an enhancement of emissions at inclined target angle.     

A Layered-Encoding Cascade Optimization Approach to Product-Mix Planning in High-Mix–Low-Volume Manufacturing

High-mix-low-volume (HMLV) production is currently a worldwide manufacturing trend. It requires a high degree of customization in the manufacturing process to produce a wide range of products in low quantity in order to meet customers' demand for more variety and choices of products. Such a kind of business environment has increased the conversion time and decreased the production efficiency due to frequent production changeover. In this paper, a layered-encoding cascade optimization (LECO) approach is proposed to develop an HMLV product-mix optimizer that exhibits the benefits of low conversion time, high productivity, and high equipment efficiency. Specifically, the genetic algorithm (GA) and particle swarm optimization (PSO) techniques are employed as optimizers for different decision layers in different LECO models. Each GA and PSO optimizer is studied and compared. A number of hypothetical and real data sets from a manufacturing plant are used to evaluate the performance of the proposed GA and PSO optimizers. The results indicate that, with a proper selection of the GA and PSO optimizers, the LECO approach is able to generate high-quality product-mix plans to meet the production demands in HMLV manufacturing environments.