Use of Ozonated Water for Disinfecting Gastrointestinal Endoscopes

The reprocessing of endoscopes is a complex procedure due to their structural design. In the constant search for new antimicrobial substances, recent studies with ozone have yielded great benefits. The present study evaluated the effects of ozonated water used to disinfect endoscopes comparing its efficacy with the conventional technique (2% glutaraldehyde). According to the results obtained, when ozonated water was used (330 mg.min.L^?1), induced a 2 log reduction of the viable microorganisms under the conditions tested. Ozonated water was a potent gastrointestinal endoscopic sanitizer, suggesting it is a feasible alternative for disinfection.     

Easy mass spectrometry for metabolomics and quality control of vegetable and animal fats

Easy ambient sonic spray ionization (EASI), a novel desorption/ionization technique for ambient mass spectrometry analysis, is shown to permit the characterization of different types of vegetable and animal fats. The taxonomic markers of the oils, mainly fatty acids and phenols, are extracted with methanol/water (1:1) solution and made alkaline with NH₄OH, then placed and dried on the surface of a glass tip and directly analyzed by EASI‐MS in the negative‐ion mode. EASI provides a supersonic cloud of charged droplets that causes efficient desorption and ionization of the oil markers directly from the surface of the glass tip. As proof‐of‐principle cases, EASI(?)‐MS was applied to genuine samples of olive oil, hazelnut oil, soybean oil, grape seed oil, canola oil, butter, and lard. Characteristic metabolomics EASI(?)‐MS profiles of fatty acids and eventually phenols were obtained.     

Determination of catechins in green tea infusions by reduced flow micellar electrokinetic chromatography

A sulfated-β-cyclodextrin (s-β-CD) modified reduced flow micellar electrokinetic chromatography (RF-MEKC) method was developed and validated for the determination of catechins in green tea. The optimal electrolyte consisted of 0.2% triethylamine, 50 mmol/L SDS and 0.8% s-β-CD (pH = 2.9), allowing baseline separation of five catechins in 4 min. The samples and standards were injected at 0.6 psi for 5 s under constant voltage of −30 kV. Sample preparation simply involved extraction of 2 g of tea with 200 mL water at 95 °C under constant stirring for 5 min. The method demonstrated excellent performance, with limits of detection (LOD) and quantification (LOQ) of 0.02–0.1 and 0.1–0.5 μg/mL, respectively, and recovery percentages of 94–101%. The method was applied to six samples of Brazilian green tea infusions. Epigallocatechin gallate (23.4–112.4 μg/mL) was the major component, followed by epigallocatechin (18.4–78.9 μg/mL), epicatechin gallate (5.6–29.6 μg/mL), epicatechin (4.6–14.5 μg/mL) and catechin (3.2–8.2 μg/mL).     

Comparative Analysis of Ozone and Ultrasound Effect on the Elimination of Giardia spp. Cysts from Wastewater

Giardia spp. is a flagellate protozoan that presents two evolution forms, cysts and trophozoites. Cysts are resistant to chlorine, the most employed disinfectant agent in the treatment of water. For this reason, new techniques for the disinfection of waters that contain this parasite are necessary. This work evaluated the efficiency of the disinfection by ozone and ultrasound individually and simultaneously upon wastewater. The data obtained showed that after application, ozone, ultrasound, and combined techniques induced a significant elimination of Giardia spp. cysts. Furthermore, this effect was more accentuated when the two techniques were applied simultaneously.     

New carbon composite adsorbents for the removal of textile dyes from aqueous solutions: Kinetic,equilibrium, and thermodynamic studies

New carbon composite materials were prepared by pyrolysis of mixture of coffee wastes and red mud at 700 °C with the inorganic: organic ratios of 1.9 (CC-1.9) and 2.2 (CC-2.2). These adsorbents were used to remove reactive orange 16 (RO-16) and reactive red 120 (RR-120) textile dyes from aqueous solution. The CC-1.9 and CC-2.2 materials were characterized using Fourier transform infrared spectroscopy, Nitrogen adsorption/desorption curves, scanning electron Microscopy and X-ray diffraction. The kinetic of adsorption data was fitted by general order kinetic model. A three-parameter isotherm model, Liu isotherm model, gave the best fit of the equilibrium data (298 to 323 K). The maximum amounts of dyes removed at 323 K were 144.8 (CC-1.9) and 139.5 mg g^?1 (CC-2.2) for RO-16 dye and 95.76 (CC-1.9) and 93.80 mg g^?1 (CC-2.2) for RR-120 dye. Two simulated dyehouse effluents were used to investigate the application of the adsorbents for effluent treatment.     

Power limits for secondary devices operating on TV white spaces

The use of TV white spaces as an alternative to overcome spectrum scarcity is a huge opportunity for new telecommunication systems and services. While being attractive for its desirable propagation characteristics, this part of the spectrum imposes a major difficulty from design and regulatory perspectives: how to optimize the use of spectrum and to ensure the protection of primary users, TV systems for example, at the same time. This paper discusses strategies to be adopted by geo-location database operators to calculate adaptive maximum permitted power levels for secondary devices, according to permissible levels of interference into the digital terrestrial television primary system.     

Pre-emptive versus non-pre-emptive real time scheduling in intelligent mobile robotics

Autonomous and semi-autonomous mobile robots have to perform a multiplicity of concurrent activities in order to carry out useful tasks in unstructured human-populated environments. Even if it is commonly accepted that a successful accomplishment of assigned tasks requires some sort of real time capability to quickly react and adapt to environmental changes, it is not clear which operating system support is best suited for the scheduling and synchronizing of concurrent activities with different timing requirements. This paper discusses this problem, comparing two different real time scheduling policies for autonomous robot applications: pre-emptive rate monotonic and non pre-emptive Earliest Deadline First (EDF). Experimental results are presented and evaluated.     

Photochemical grafting of acrylated azo dyes onto polymeric surfaces. VII. Kinetics and mechanism of dye-sensitized photoinitiation of some diacrylates

Photoinitiated grafting and graft polymerization of liquid mixtures, adsorbed onto polypropylene, polycaprolactam, and poly(ethylene terephthalate) films, containing one of four acryloxy-substituted aromatic diazenes and one of four diacrylate comonomers, in the presence of 1,2-diphenyl-2,2-dimethoxyethanone as photoinitiator, were investigated kinetically at 30 ± 2°C. Irradiation was carried out polychromatically, with impinging photoenergy from 2.1 × 10^?8 to 20.5 × 10^?8 einstein s^?1 cm^?2; in some of the runs the ultraviolet radiation was filtered. The ratio R between the molar concentration of photoinitiator and the sum of concentrations of dye and diacrylate varied between 0.005 and 0.095; the ratio M between the molar concentration of dye and diacrylate varied between 0.005 and 0.046. The moles of dye and diacrylate n initially deposited per unit apparent polymeric surface S varied between 2 and 74 μmol cm^?2. No selective effect was shown by the presence of dyes in the comonomer mixture. The surface density of grafted molecules at the end of the grafting process was not affected by the photoinitiator concentration (for 0.030 < R < 0.095), by diacrylate or dye concentrations, or by the kind of polymer substrate. This parameter, on the contrary, clearly depended on n/S, and linearly up to n/S ? 30 μmol cm^?2. Quantum efficiencies for the two consecutive kinetic processes of grafting and graft polymerization (Φ₁ and Φ₂, respectively) were evaluated. The dependency of Φ₁ on R, as well as of Φ₂ on n/S, are critically discussed on the basis of the proposed mechanism involving grafting of an oligomeric chain (Φ₁ values up to the order of 10²) followed by a step-by-step graft polymerization (Φ₂ limiting values of the order of unity). The sensitizing effect of acryloxy-substituted aromatic diazenes on both Φ₁ and Φ₂ is evidenced.     

Integral transform solution for hyperbolic heat conduction in a finite slab

An analytical integral transformation of the thermal wave propagation problem in a finite slab is obtained through the generalized integral transform technique (GITT). The use of the GITT approach in the analysis of the hyperbolic heat conduction equation leads to a coupled system of second order ordinary differential equations in the time variable. The resulting transformed ODE system is then numerically solved by Gear's method for stiff initial value problems. Numerical results are presented for the local and average temperatures with different Biot numbers and dimensionless thermal relaxation times, permitting a critical evaluation of the technique performance. A comparison is also performed with previously reported results in the literature for special cases and with those produced through the application of the Laplace transform method (LTM), and the finite volume-Gear method (FVGM).