Search results for " Separation"
showing 10 items of 724 documents
Mathematical Models and their Solutions for Domains of Compex Form
2014
Promocijas darbā tiek apskatīti dažādi oriģināli modeļi un to risinājumi sarežģītas formas apgabaliem. Intensīvās tērauda rūdīšanas procesi sistēmām ar ribām tiek aprakstīti ar 3D hiperbolisko, kā arī ar klasisko siltuma vadīšanas vienādojumu. Precīzā atrisinājuma iegūšanai izmantota Grīna funkciju metode un tās vispārinājums. Modernajos datoros sastopamajām sistēmām ar dubulsieniņu un dubultribu dota stacionārā un nestacionārā siltumvadīšanas problēma 2D gadījumā. Tās risinājums tiek iegūts ar konservatīvās viduvēšanas metodi, galīgo diferenču metodi un tās modifikāciju robežnosacījumiem. Piedāvāts jauns matemātiskais modelis vītola flautai, problēmas formulējumā izmantojot 1D lineāru viļņ…
Negative pressure cavitation extraction and antioxidant activity of genistein and genistin from the roots of pigeon pea [Cajanus cajan (L.) Millsp.]
2010
Abstract A new method—negative pressure cavitation extraction (NPCE) was proposed and investigated for the extraction of the main isoflavonoids, namely genistein and genistin from pigeon pea roots. The effects of extraction time and particle size on the extraction yields were firstly optimized, then a central composite design (CCD) combined with response surface methodology (RSM) was used to study the effects of negative pressure, ethanol concentration and liquid/solid ratio on the extraction yields. The maximum extraction yields of genistein and genistin reached 0.418 and 0.398 mg/g, respectively, under the optimal conditions: extraction time 45 min, particle size 50 mesh, negative pressur…
Inside Cover: Hydrogen-Bonded Open-Framework with Pyridyl-Decorated Channels: Straightforward Preparation and Insight into Its Affinity for Acidic Mo…
2017
International audience; A hydrogen-bonded open framework with pores decorated by pyridyl groups was constructed by off-charge-stoichiometry assembly of protonated tetrakis(4-pyridyloxymethyl)methane and [Al(oxalate)(3)](3-), which are the H-bond donor and acceptor of ionic H-bond interactions, respectively. This supramolecular porous architecture (SPA-2) has 1nm-large pores interconnected in 3D with large solvent-accessible void (53%). It demonstrated remarkable affinity for acidic organic molecules in solution, which was investigated by means of various carboxylic acids including larger drug molecules. Competing sorption between acetic acid and its halogenated homologues evidenced good sel…
Evidence of Mechanisms Occurring in Thermally Induced Phase Separation of Polymeric Systems
2014
Thermally induced phase separation is a fabrication technique for porous polymeric structures. By means of easy-to-tune processing parameters, such as system composition and demixing temperature, a vast latitude of average pore dimensions, pore size distributions, and morphologies can be obtained. The relation between demixing temperature and morphology was demonstrated via cloud point curve measurement and foams fabrication with controlled thermal protocols, for the model system poly-l-lactide–dioxane–water. The morphologies obtained at a temperature lower than cloud point showed a closed-pore architecture, suggesting a “nucleation-and-growth” separation mechanism, which produced larger po…
Simultaneous screening and quantification of aminoglycoside antibiotics in honey using mixed-mode liquid chromatography with quadrupole time-of-fligh…
2018
An analytical method based on liquid chromatography with quadrupole time-of-flight mass spectrometry has been developed for the simultaneous determination of six aminoglycoside antibiotics in honey. The sample pretreatment included extraction with aqueous trichloroacetic acid followed by solid-phase extraction on Strata-X polymeric reversed phase cartridges. Liquid chromatography separation was performed on an Obelisc R zwitterionic type mixed-mode column. An ionBooster™ heated electrospray source was used and showed enhanced ionization efficiency in comparison to a conventional electrospray source. The observed signal enhancement ranged from 3- (neomycin) to 16-fold (gentamicin C1). A data…
Cadmium mass measurements between the neutron shell closures at N=50 and 82
2010
International audience; The mass values of the neutron-deficient cadmium isotopes 99−109Cd and of the neutronrich isotopes 114,120,122−124,126,128Cd have been measured using ISOLTRAP. The behavior of the separation energies of the cadmium isotopes from N = 50 to 82 is discussed.
Engineered Membranes for Residual Cell Trapping on Microfluidic Blood Plasma Separation Systems: A Comparison between Porous and Nanofibrous Membranes
2021
Blood-based clinical diagnostics require challenging limit-of-detection for low abundance, circulating molecules in plasma. Micro-scale blood plasma separation (BPS) has achieved remarkable results in terms of plasma yield or purity, but rarely achieving both at the same time. Here, we proposed the first use of electrospun polylactic-acid (PLA) membranes as filters to remove residual cell population from continuous hydrodynamic-BPS devices. The membranes hydrophilicity was improved by adopting a wet chemistry approach via surface aminolysis as demonstrated through Fourier Transform Infrared Spectroscopy and Water Contact Angle analysis. The usability of PLA-membranes was assessed through de…
Exploring Bioequivalence of Dexketoprofen Trometamol Drug Products with the Gastrointestinal Simulator (GIS) and Precipitation Pathways Analyses
2019
The present work aimed to explain the differences in oral performance in fasted humans who were categorized into groups based on the three different drug product formulations of dexketoprofen trometamol (DKT) salt&mdash
Influence of annealing conditions on the photoelectrocatalytic performance of WO3 nanostructures
2020
[EN] Nanostructured WO3 photoanodes have been synthesized by electrochemical anodization under controlled hydrodynamic conditions in acidic media in the presence of 0.05 M H2O2. Subsequently, samples have been subjected to a thermal treatment (annealing) at different temperatures (400 degrees C, 500 degrees C and 600 degrees C) and under different gaseous atmospheres (air, N-2, Ar). The influence of these annealing conditions on the morphology, crystallinity, photoelectrochemical behavior and dopant chemistry of the different photoanodes has been investigated through Electronic Microscopy, Raman Spectroscopy, Photoelectrochemical Impedance Spectroscopy and Mott-Schottky analysis. In general…
PIPERADE: A double Penning trap for mass separation and mass spectrometry at DESIR/SPIRAL2
2021
International audience; A double Penning trap is being commissioned at CENBG Bordeaux for the future DESIR/SPIRAL2 facility of GANIL. The setup is designed to perform both high-resolution mass separation of the ion beam for trap-assisted spectroscopy, and high-accuracy mass spectrometry of short-lived nuclides. In this paper, the technical details of the new device are described. First offline tests with the purification trap are also presented, showing a mass resolving power of about 105.