Search results for "Electromagnet"
showing 10 items of 1862 documents
Data for: Analytical induced force solution in conducting cylindrical bodies and rings due to a rotating finite permanent magnet
2019
Implementation of analytical current density solution in numerical calculations using Wolfram Mathematica software. THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOVE
Photon absorption by aqueous TiO2 dispersion contained in a stirred photoreactor
1991
We present a simple experimental method which allows the evaluation of the absorbed photon flow. The method is based on measurements of transmitted photon rates (by means of standard actinometer solutions) for different reactor thicknesses and/or catalyst concentrations. The method was applied to phenol degradation reaction carried out in a stirred batch phtotoreactor containing aqueous TiO 2 (anatase) dispersion, directly irradied by a 1,500 W Xe lamp
Rate of photon absorption and turnover number: two parameters for the comparison of heterogeneous photocatalytic systems in a quantitative way
1993
Abstract In order to correctly compare the performance of different photocatalytic systems using polycrystalline semiconductor oxides, two parameters are proposed: the rate of photon absorption (rpa) and the turnover number (tn). From these quantities the quantum yield (qy), which indicates the efficiency of the absorbed photons for promoting a reaction event, can be determined. The phenol photodegradation reaction, carried out in aqueous dispersions of polycrystalline TiO2 (anatase) of different preparation methods and sources, has been used as “test reaction” in order to determine the tn, rpa and qy values.
ChemInform Abstract: Rate of Photon Absorption and Turnover Number: Two Parameters for the Comparison of Heterogeneous Photocatalytic Systems in a Qu…
2010
Abstract In order to correctly compare the performance of different photocatalytic systems using polycrystalline semiconductor oxides, two parameters are proposed: the rate of photon absorption (rpa) and the turnover number (tn). From these quantities the quantum yield (qy), which indicates the efficiency of the absorbed photons for promoting a reaction event, can be determined. The phenol photodegradation reaction, carried out in aqueous dispersions of polycrystalline TiO2 (anatase) of different preparation methods and sources, has been used as “test reaction” in order to determine the tn, rpa and qy values.
Brown Carbon Aerosol in Urban Xi'an, Northwest China: The Composition and Light Absorption Properties.
2018
Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) w…
Dimensionless Analysis Of Slurry Photocatalytic Reactors Using Two-Flux And Six-Flux Radiation Absorption-Scattering Models
2007
Photocatalytic oxidation (PCO) over titanium dioxide (TiO2) is a "green" sustainable process for the treatment and purification of water and wastewater. However,the application of PCO for wastewater treatment on an industrial scale is currently hindered by a lack of simple mathematical models that can be readily applied to reactor design. Current models are either too simplistic or too rigorous to be useful in photocatalytic reactor design, scale-up, and optimization. In this paper a simple mathematical model is presented for slurry, annular, photocatalytic reactors that still retains the essential elements of a rigorous approach while providing simple solutions. The model extends the appli…
Changes in Body Composition in Anorexia Nervosa : Predictors of Recovery and Treatment Outcome
2015
The restoration of body composition (BC) parameters is considered to be one of the most important goals in the treatment of patients with anorexia nervosa (AN). However, little is known about differences between AN diagnostic subtypes [restricting (AN-R) and binge/purging (AN-BP)] and weekly changes in BC during refeeding treatment. Therefore, the main objectives of our study were twofold: 1) to assess the changes in BC throughout nutritional treatment in an AN sample and 2) to analyze predictors of BC changes during treatment, as well as predictors of treatment outcome. The whole sample comprised 261 participants [118 adult females with AN (70 AN-R vs. 48 AN-BP), and 143 healthy controls].…
Understanding the ring current effects on magnetic shielding of hydrogen and carbon nuclei in naphthalene and anthracene
2008
The local response to an external magnetic field normal to the molecular plane of naphthalene and anthracene was investigated via current density and magnetic shielding density maps. The Biot-Savart law shows that the deshielding caused by pi-ring currents in naphthalene is stronger for alpha- than for beta-protons due to geometrical factors. The shielding tensor of the carbon nuclei in both molecules is strongly anisotropic and its out-of-plane component determines the up-field chemical shift of (13)C in nuclear magnetic resonance spectra. The pi-ring currents flowing beyond the C-skeleton in front of a probe carbon nucleus, and on remote parts of the molecular perimeter, yield positive co…
Optical Switching and Antenna Effect of Dendrimers with an Anthracene Core
2007
Dendrimers 6G(i) (i=1-4) consisting of an anthracene core and Fréchet dendrons which are attached via a CH(2)OCH(2) chain in the 9-position undergo quantitative and completely reversible intramolecular [4pi+4pi] cycloaddition. The process can be monitored by absorption and fluorescence measurements. The Fréchet dendrons act as an energy funnel that collects and focuses the photon energy but does not change the photostationary states, which for both directions are completely on the product side when the separate chromophores are selectively irradiated. The quantum yields of anthracene fluorescence and of singlet energy transfer from the dendrons to the core were studied as a function of dend…
Efficient transfer of positrons from a buffer-gas-cooled accumulator into an orthogonally oriented superconducting solenoid for antihydrogen studies
2012
Positrons accumulated in a room-temperature buffer-gas-cooled positron accumulator are efficiently transferred into a superconducting solenoid which houses the ATRAP cryogenic Penning trap used in antihydrogen research. The positrons are guided along a 9 m long magnetic guide that connects the central field lines of the 0.15 T field in the positron accumulator to the central magnetic field lines of the superconducting solenoid. Seventy independently controllable electromagnets are required to overcome the fringing field of the large-bore superconducting solenoid. The guide includes both a 15° upward bend and a 105° downward bend to account for the orthogonal orientation of the positron accu…