Search results for "Equipment Design"
showing 10 items of 409 documents
Study of aerobic granular sludge stability in a continuous-flow membrane bioreactor.
2015
A granular continuous-flow membrane bioreactor with a novel hydrodynamic configuration was developed to evaluate the stability of aerobic granular sludge (AGS). Under continuous-flow operation (Period I), AGS rapidly lost their structural integrity resulting in loose and fluffy microbial aggregates in which filamentous bacteria were dominant. The intermittent feeding (Period II) allowed obtaining the succession of feast and famine conditions that favored the increase in AGS stability. Although no further breakage occurred, the formation of new granules was very limited, owing to the absence of the hydraulic selection pressure. These results noted the necessity to ensure, on the one hand the…
Urea as a PCDD/F inhibitor in municipal waste incineration.
2001
Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from municipal waste incineration have been widely studied because of their extensive toxicity, and many efforts have been made to restrict their emissions. Although a number of chemical compounds have been shown in laboratory-scale tests to inhibit the formation of PCDD/Fs, few have been tested in pilot- or full-scale plants. This work evaluates the effect of urea as a PCDD/F inhibitor in a pilot-scale incinerator that uses refuse-derived fuel (RDF). The decomposition of urea under the test conditions was also studied using detailed kinetic modeling. An aqueous solution of urea was injected into the flue gas stream …
Multicomponent polymeric micelles based on polyaspartamide as tunable fluorescent pH-window biosensors
2010
Abstract PHEA-PEG 5000 -C 16 is a polyaspartamide polymer with appended hydrophilic PEG 5000 functions and hydrophobic n-C 16 units forming biocompatible micelles with a CAC as low as 1.8 × 10 −7 M. The protonation and acidity constants of the polymer's amino and carboxylic groups have been determined by potentiometric titrations at five different concentrations higher than CAC, finding concentration-independent values. Viscosity and polarity of the micellar core have been investigated by means of fluorescent probes, finding local values comparable to those of pure toluene and to the core of sodium dodecyl sulphate micelles, independently on the protonation degree of the polymer. The fluor…
Impact Acceleration During Prolonged Running While Wearing Conventional Versus Minimalist Shoes.
2020
Purpose: In recent years a sub-group of minimalist runners have emerged who aim to perform physical exercise more naturally in an attempt to reduce running-related injuries. Here we aimed to determine the effect that running with minimalist footwear in a prolonged run has on footimpact accelerations. Method: Seventeen runners ran with minimalist and conventional shoes (MS and CS, respectively) in two separate sessions; the participants had experience with both footwear types. We measured the length and frequency of each stride, as well as the tibial and head impact acceleration every 5 minutes during a prolonged run (30 minutes at 80% of each individual's maximum aerobic speed). Results: Th…
Twin axial vortices generated by Fibonacci lenses.
2013
Optical vortex beams, generated by Diffractive Optical Elements (DOEs), are capable of creating optical traps and other multifunctional micromanipulators for very specific tasks in the microscopic scale. Using the Fibonacci sequence, we have discovered a new family of DOEs that inherently behave as bifocal vortex lenses, and where the ratio of the two focal distances approaches the golden mean. The disctintive optical properties of these Fibonacci vortex lenses are experimentally demonstrated. We believe that the versatility and potential scalability of these lenses may allow for new applications in micro and nanophotonics.
Formation and transformation of carbon nanoparticles under electron irradiation.
2004
This article reviews the phenomena occurring during irradiation of graphitic nanoparticles with high–energy electrons. A brief introduction to the physics of the interaction between energetic electrons and solids is given with particular emphasis on graphitic materials. Irradiation effects are discussed, starting from microscopic mechanisms that lead to structural alterations of the graphite lattice. It is shown how random displacements of the atoms and their subsequent rearrangements eventually lead to topological changes of the nanoparticles. Examples are the formation of carbon onions, morphological changes of carbon nanotubes, or the coalescence of fullerenes or nanotubes under electron…
Modified apparatus for voltage gradient gel electrophoresis.
1999
We built a modified version of voltage gradient gel electrophoresis system to correct distortions in nucleic acids electrophoretic migration patterns occurring at the edges of the gel when the original voltage gradient apparatus is used. The new device allows correct fractionation of nucleic acids also when electrophoresis is performed at high voltages.
A study of reproducibility of kinesiology tape applications: review, reliability and validity
2017
Abstract Background Literature addressing the mechanical properties of kinesiology tape is quite scarce. There are no studies which focus on the mechanical characteristics of kinesiology tape, its mechanical properties, nor its adherence following the ISO international standard test methods for tape elongation. Methods This study quantified the mechanical characteristics of 380 samples of kinesiology tape from 19 different brands and in 4 different colors using a dynamometer. Mechanical testing was controlled by UNE EN ISO 13934-1. Results Significant differences were found between tape brands in terms of grammage, maximum force tenacity, work, pre-elongation and percentage elongation (P < …
Landfill gas upgrading with countercurrent water wash.
2006
A pilot-scale countercurrent absorption process for upgrading landfill gas to produce vehicle fuel was studied using absorption and desorption units and water as absorbent. The height-to-diameter ratio of the absorption column used was 3:1 instead of the more conventionally used 20:1 ratio, and a higher pressure was used along with a lower water flow rate. The effects of pressure (10-30 bar) and water and gas flow-ratios on the upgrading process were studied. Methane content in the product gas increased to near or above 90% with both gas flows (50 and 100 l/min) used at over 20 bar pressure with 10 l/min water flow and at 30 bar pressure with 5l/min water flow. Carbon dioxide content with t…
Dosimetric perturbations of a lead shield for surface and interstitial high-dose-rate brachytherapy.
2014
In surface and interstitial high-dose-rate brachytherapy with either (60)Co, (192)Ir, or (169)Yb sources, some radiosensitive organs near the surface may be exposed to high absorbed doses. This may be reduced by covering the implants with a lead shield on the body surface, which results in dosimetric perturbations. Monte Carlo simulations in Geant4 were performed for the three radionuclides placed at a single dwell position. Four different shield thicknesses (0, 3, 6, and 10 mm) and three different source depths (0, 5, and 10 mm) in water were considered, with the lead shield placed at the phantom surface. Backscatter dose enhancement and transmission data were obtained for the lead shields…